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Baldwin KT, Murai KK, Khakh BS. Astrocyte morphology. Trends Cell Biol 2024; 34:547-565. [PMID: 38180380 DOI: 10.1016/j.tcb.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/18/2023] [Accepted: 09/29/2023] [Indexed: 01/06/2024]
Abstract
Astrocytes are predominant glial cells that tile the central nervous system (CNS). A cardinal feature of astrocytes is their complex and visually enchanting morphology, referred to as bushy, spongy, and star-like. A central precept of this review is that such complex morphological shapes evolved to allow astrocytes to contact and signal with diverse cells at a range of distances in order to sample, regulate, and contribute to the extracellular milieu, and thus participate widely in cell-cell signaling during physiology and disease. The recent use of improved imaging methods and cell-specific molecular evaluations has revealed new information on the structural organization and molecular underpinnings of astrocyte morphology, the mechanisms of astrocyte morphogenesis, and the contributions to disease states of reduced morphology. These insights have reignited interest in astrocyte morphological complexity as a cornerstone of fundamental glial biology and as a critical substrate for multicellular spatial and physiological interactions in the CNS.
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Affiliation(s)
- Katherine T Baldwin
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Montreal, QC H3G 1A4, Canada.
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA; Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA.
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2
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Li D, Wang Y, Guo Y, Wang W. Bioinformatics analysis reveals multiple functional changes in astrocytes in temporal lobe epilepsy. Brain Res 2024; 1831:148820. [PMID: 38417653 DOI: 10.1016/j.brainres.2024.148820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 02/14/2024] [Accepted: 02/20/2024] [Indexed: 03/01/2024]
Abstract
Epilepsy is a prevalent chronic neurological disorder characterized by recurrent seizures and brain dysfunction. Existing antiepileptic drugs (AEDs) mainly act on neurons and provide symptomatic control of seizures, but they do not modify the progression of epilepsy and may cause serious adverse effects. Increasing evidence suggests that reactive astrogliosis is critical in the pathophysiology of epilepsy. However, the function of reactive astrocytes in epilepsy has not been thoroughly explored. To provide a new perspective on the role of reactive astrocytes in epileptogenesis, we identified human astrocyte-specific genes and found 131 of these genes significantly differentially expressed in human temporal lobe epilepsy (TLE) datasets. Multiple astrocytic functions, such as cell adhesion, cell morphogenesis, actin filament-based process, apoptotic cell clearance and response to oxidative stress, were found to be promoted. Moreover, multiple altered astrocyte-specific genes were enriched in phagocytosis, perisynaptic astrocyte processes (PAPs), plasticity, and synaptic functions. Nine hub genes (ERBB2, GFAP, NOTCH2, ITGAV, ABCA1, AQP4, LRP1, GJA1, and YAP1) were identified by protein-protein interaction (PPI) network analysis. The correlation between the expression of these hub genes and seizure frequency, as well as epilepsy-related factors, including inflammatory mediators, complement factors, glutamate excitotoxicity and astrocyte reactivity, were analyzed. Additionally, upstream transcription factors of the hub genes were predicted. Finally, astrogliosis and the expression of the hub genes were validated in an epileptic rat model. Our findings reveal the various changes in astrocyte function associated with epilepsy and provide candidate astrocyte-specific genes that could be potential antiepileptogenic targets.
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Affiliation(s)
- Dongxiao Li
- Department of Neurology, The Second Hospital of Hebei Medical University, 215 Heping West Road, Shijiazhuang, Hebei 050000, China; Neurological Laboratory of Hebei Province, The Second Hospital of Hebei Medical University, 215 Heping West Road, Shijiazhuang, Hebei 050000, China
| | - Yufeng Wang
- Cancer Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Yansu Guo
- Beijing Geriatric Healthcare Center, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Municipal Geriatric Medical Research Center, Beijing, China
| | - Weiping Wang
- Department of Neurology, The Second Hospital of Hebei Medical University, 215 Heping West Road, Shijiazhuang, Hebei 050000, China; Neurological Laboratory of Hebei Province, The Second Hospital of Hebei Medical University, 215 Heping West Road, Shijiazhuang, Hebei 050000, China.
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3
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Vieira R, Mariani JN, Huynh NPT, Stephensen HJT, Solly R, Tate A, Schanz S, Cotrupi N, Mousaei M, Sporring J, Benraiss A, Goldman SA. Young glial progenitor cells competitively replace aged and diseased human glia in the adult chimeric mouse brain. Nat Biotechnol 2024; 42:719-730. [PMID: 37460676 PMCID: PMC11098747 DOI: 10.1038/s41587-023-01798-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 04/20/2023] [Indexed: 08/26/2023]
Abstract
Competition among adult brain cells has not been extensively researched. To investigate whether healthy glia can outcompete diseased human glia in the adult forebrain, we engrafted wild-type (WT) human glial progenitor cells (hGPCs) produced from human embryonic stem cells into the striata of adult mice that had been neonatally chimerized with mutant Huntingtin (mHTT)-expressing hGPCs. The WT hGPCs outcompeted and ultimately eliminated their human Huntington's disease (HD) counterparts, repopulating the host striata with healthy glia. Single-cell RNA sequencing revealed that WT hGPCs acquired a YAP1/MYC/E2F-defined dominant competitor phenotype upon interaction with the host HD glia. WT hGPCs also outcompeted older resident isogenic WT cells that had been transplanted neonatally, suggesting that competitive success depended primarily on the relative ages of competing populations, rather than on the presence of mHTT. These data indicate that aged and diseased human glia may be broadly replaced in adult brain by younger healthy hGPCs, suggesting a therapeutic strategy for the replacement of aged and diseased human glia.
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Affiliation(s)
- Ricardo Vieira
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
| | - John N Mariani
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Nguyen P T Huynh
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
- Sana Biotechnology, Inc, Cambridge, MA, USA
| | - Hans J T Stephensen
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
- Department of Computer Science, University of Copenhagen Faculty of Science, Copenhagen, Denmark
| | - Renee Solly
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
- Sana Biotechnology, Inc, Cambridge, MA, USA
| | - Ashley Tate
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
- Sana Biotechnology, Inc, Cambridge, MA, USA
| | - Steven Schanz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Natasha Cotrupi
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Marzieh Mousaei
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
| | - Jon Sporring
- Department of Computer Science, University of Copenhagen Faculty of Science, Copenhagen, Denmark
| | - Abdellatif Benraiss
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Steven A Goldman
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark.
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, USA.
- Sana Biotechnology, Inc, Cambridge, MA, USA.
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4
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Reis FMCV, Maesta-Pereira S, Ollivier M, Schuette PJ, Sethi E, Miranda BA, Iniguez E, Chakerian M, Vaughn E, Sehgal M, Nguyen DCT, Yuan FTH, Torossian A, Ikebara JM, Kihara AH, Silva AJ, Kao JC, Khakh BS, Adhikari A. Control of feeding by a bottom-up midbrain-subthalamic pathway. Nat Commun 2024; 15:2111. [PMID: 38454000 PMCID: PMC10920831 DOI: 10.1038/s41467-024-46430-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 02/26/2024] [Indexed: 03/09/2024] Open
Abstract
Investigative exploration and foraging leading to food consumption have vital importance, but are not well-understood. Since GABAergic inputs to the lateral and ventrolateral periaqueductal gray (l/vlPAG) control such behaviors, we dissected the role of vgat-expressing GABAergic l/vlPAG cells in exploration, foraging and hunting. Here, we show that in mice vgat l/vlPAG cells encode approach to food and consumption of both live prey and non-prey foods. The activity of these cells is necessary and sufficient for inducing food-seeking leading to subsequent consumption. Activation of vgat l/vlPAG cells produces exploratory foraging and compulsive eating without altering defensive behaviors. Moreover, l/vlPAG vgat cells are bidirectionally interconnected to several feeding, exploration and investigation nodes, including the zona incerta. Remarkably, the vgat l/vlPAG projection to the zona incerta bidirectionally controls approach towards food leading to consumption. These data indicate the PAG is not only a final downstream target of top-down exploration and foraging-related inputs, but that it also influences these behaviors through a bottom-up pathway.
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Affiliation(s)
- Fernando M C V Reis
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Sandra Maesta-Pereira
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Matthias Ollivier
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Peter J Schuette
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Ekayana Sethi
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Blake A Miranda
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Emily Iniguez
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Meghmik Chakerian
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Eric Vaughn
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Megha Sehgal
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, USA
| | - Darren C T Nguyen
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Faith T H Yuan
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Anita Torossian
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Juliane M Ikebara
- Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Bernardo do Campo, SP, 09606-070, Brazil
| | - Alexandre H Kihara
- Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Bernardo do Campo, SP, 09606-070, Brazil
| | - Alcino J Silva
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, USA
- Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, USA
| | - Jonathan C Kao
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Avishek Adhikari
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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5
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Ollivier M, Soto JS, Linker KE, Moye SL, Jami-Alahmadi Y, Jones AE, Divakaruni AS, Kawaguchi R, Wohlschlegel JA, Khakh BS. Crym-positive striatal astrocytes gate perseverative behaviour. Nature 2024; 627:358-366. [PMID: 38418885 PMCID: PMC10937394 DOI: 10.1038/s41586-024-07138-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 01/31/2024] [Indexed: 03/02/2024]
Abstract
Astrocytes are heterogeneous glial cells of the central nervous system1-3. However, the physiological relevance of astrocyte diversity for neural circuits and behaviour remains unclear. Here we show that a specific population of astrocytes in the central striatum expresses μ-crystallin (encoded by Crym in mice and CRYM in humans) that is associated with several human diseases, including neuropsychiatric disorders4-7. In adult mice, reducing the levels of μ-crystallin in striatal astrocytes through CRISPR-Cas9-mediated knockout of Crym resulted in perseverative behaviours, increased fast synaptic excitation in medium spiny neurons and dysfunctional excitatory-inhibitory synaptic balance. Increased perseveration stemmed from the loss of astrocyte-gated control of neurotransmitter release from presynaptic terminals of orbitofrontal cortex-striatum projections. We found that perseveration could be remedied using presynaptic inhibitory chemogenetics8, and that this treatment also corrected the synaptic deficits. Together, our findings reveal converging molecular, synaptic, circuit and behavioural mechanisms by which a molecularly defined and allocated population of striatal astrocytes gates perseveration phenotypes that accompany neuropsychiatric disorders9-12. Our data show that Crym-positive striatal astrocytes have key biological functions within the central nervous system, and uncover astrocyte-neuron interaction mechanisms that could be targeted in treatments for perseveration.
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Affiliation(s)
- Matthias Ollivier
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Joselyn S Soto
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kay E Linker
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Stefanie L Moye
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Anthony E Jones
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Riki Kawaguchi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
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6
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Li Q, Zhou B, Su M, Liao P, Lei F, Li X, Liao D, Zhang X, Jiang R. Visualization and Characterization of the Brain Regional Heterogeneity of Astrocyte-Astrocyte Structural Interactions by Using Improved Iontophoresis with Dual-Fluorescent Dyes. Brain Sci 2023; 13:1644. [PMID: 38137092 PMCID: PMC10741863 DOI: 10.3390/brainsci13121644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
Astrocytes are morphologically intricate cells and actively modulate the function of the brain. Through numerous fine processes, astrocytes come into contact with neurons, blood vessels, and other glia cells. Emerging evidence has shown that astrocytes exhibit brain regional diversity in their morphology, transcriptome, calcium signaling, and functions. However, little is known about the brain regional heterogeneity of astrocyte-astrocyte structural interaction. So far, the visualization and characterization of the morphological features of adjacent astrocytes have been difficult, and as a result, it is still well-accepted that astrocytes in the adult brain share non-overlapped territory. In contrast, employing an approach that combines viral labeling with dual-fluorescent dyes iontophoresis under brightfield and imaging using confocal microscopy allows for the efficient and specific labeling of adjacent astrocytes, enabling a comprehensive visualization of their fine processes and the degree of their territorial overlap. Our study in the hypothalamic regions of the brain revealed a marked spatial overlap among adjacent astrocytes, which differs from the conventional understanding based on more extensively studied regions, like the hippocampus. Additionally, we revealed the heterogeneity of the astrocyte-neuron ratio across brain regions and conducted an assessment of the photostability and labeling efficiency of fluorescent dyes used for labeling adjacent astrocytes. Our study provides new insights for studying the morphological heterogeneity of astrocytes across the central nervous system.
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Affiliation(s)
- Qingran Li
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Bin Zhou
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Mengchan Su
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Ping Liao
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Fan Lei
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xin Li
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Daqing Liao
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xia Zhang
- Department of Neurology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Ruotian Jiang
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu 610041, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
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7
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Wilton DK, Mastro K, Heller MD, Gergits FW, Willing CR, Fahey JB, Frouin A, Daggett A, Gu X, Kim YA, Faull RLM, Jayadev S, Yednock T, Yang XW, Stevens B. Microglia and complement mediate early corticostriatal synapse loss and cognitive dysfunction in Huntington's disease. Nat Med 2023; 29:2866-2884. [PMID: 37814059 PMCID: PMC10667107 DOI: 10.1038/s41591-023-02566-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 08/24/2023] [Indexed: 10/11/2023]
Abstract
Huntington's disease (HD) is a devastating monogenic neurodegenerative disease characterized by early, selective pathology in the basal ganglia despite the ubiquitous expression of mutant huntingtin. The molecular mechanisms underlying this region-specific neuronal degeneration and how these relate to the development of early cognitive phenotypes are poorly understood. Here we show that there is selective loss of synaptic connections between the cortex and striatum in postmortem tissue from patients with HD that is associated with the increased activation and localization of complement proteins, innate immune molecules, to these synaptic elements. We also found that levels of these secreted innate immune molecules are elevated in the cerebrospinal fluid of premanifest HD patients and correlate with established measures of disease burden.In preclinical genetic models of HD, we show that complement proteins mediate the selective elimination of corticostriatal synapses at an early stage in disease pathogenesis, marking them for removal by microglia, the brain's resident macrophage population. This process requires mutant huntingtin to be expressed in both cortical and striatal neurons. Inhibition of this complement-dependent elimination mechanism through administration of a therapeutically relevant C1q function-blocking antibody or genetic ablation of a complement receptor on microglia prevented synapse loss, increased excitatory input to the striatum and rescued the early development of visual discrimination learning and cognitive flexibility deficits in these models. Together, our findings implicate microglia and the complement cascade in the selective, early degeneration of corticostriatal synapses and the development of cognitive deficits in presymptomatic HD; they also provide new preclinical data to support complement as a therapeutic target for early intervention.
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Affiliation(s)
- Daniel K Wilton
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US.
| | - Kevin Mastro
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US
| | - Molly D Heller
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US
| | - Frederick W Gergits
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US
| | - Carly Rose Willing
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US
| | - Jaclyn B Fahey
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US
| | - Arnaud Frouin
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US
| | - Anthony Daggett
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at University of California, Los Angeles, CA, USA
| | - Xiaofeng Gu
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at University of California, Los Angeles, CA, USA
| | - Yejin A Kim
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US
| | - Richard L M Faull
- Department of Anatomy with Radiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Suman Jayadev
- Department of Neurology, University of Washington, Seattle, WA, USA
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Ted Yednock
- Annexon Biosciences, South San Francisco, CA, USA
| | - X William Yang
- Center for Neurobehavioral Genetics, Jane and Terry Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at University of California, Los Angeles, CA, USA
| | - Beth Stevens
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, US.
- Stanley Center, Broad Institute, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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8
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Palpagama T, Mills AR, Ferguson MW, Vikas Ankeal P, Turner C, Tippett L, van der Werf B, Waldvogel HJ, Faull RLM, Kwakowsky A. Microglial and Astrocytic Responses in the Human Midcingulate Cortex in Huntington's Disease. Ann Neurol 2023; 94:895-910. [PMID: 37528539 DOI: 10.1002/ana.26753] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/03/2023]
Abstract
OBJECTIVE Patients with Huntington's disease can present with variable difficulties of motor functioning, mood, and cognition. Neurodegeneration occurs in the anterior cingulate cortex of some patients with Huntington's disease and is linked to the presentation of mood symptomatology. Neuroinflammation, perpetrated by activated microglia and astrocytes, has been reported in Huntington's disease and may contribute to disease progression and presentation. This study sought to quantify the density of mutant huntingtin protein and neuroinflammatory glial changes in the midcingulate cortex of postmortem patients with Huntington's disease and determine if either correlates with the presentation of mood, motor, or mixed symptomatology. METHODS Free-floating immunohistochemistry quantified 1C2 immunolabeling density as an indicative marker of mutant huntingtin protein, and protein and morphological markers of astrocyte (EAAT2, Cx43, and GFAP), and microglial (Iba1 and HLA-DP/DQ/DR) activation. Relationships among the level of microglial activation, mutant huntingtin burden, and case characteristics were explored using correlative analysis. RESULTS We report alterations in activated microglia number and morphology in the midcingulate cortex of Huntington's disease cases with predominant mood symptomatology. An increased proportion of activated microglia was observed in the midcingulate of all Huntington's disease cases and positively correlated with 1C2 burden. Alterations in the astrocytic glutamate transporter EAAT2 were observed in the midcingulate cortex of patients associated with mood symptoms. INTERPRETATION This study presents pathological changes in microglia and astrocytes in the midcingulate cortex in Huntington's disease, which coincide with mood symptom presentation. These findings further the understanding of neuroinflammation in Huntington's disease, a necessary step for developing inflammation-targeted therapeutics. ANN NEUROL 2023;94:895-910.
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Affiliation(s)
- Thulani Palpagama
- Centre for Brain Research and Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Aimee Rose Mills
- Centre for Brain Research and Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Mackenzie Wendy Ferguson
- Centre for Brain Research and Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | | | - Clinton Turner
- Department of Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Lynette Tippett
- Centre for Brain Research and School of Psychology, Faculty of Sciences, University of Auckland, Auckland, New Zealand
| | - Bert van der Werf
- Department of Epidemiology and Biostatistics, Faculty of Medical and Health Sciences, School of Population Health, University of Auckland, Auckland, New Zealand
| | - Henry John Waldvogel
- Centre for Brain Research and Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Richard Lewis Maxwell Faull
- Centre for Brain Research and Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Andrea Kwakowsky
- Centre for Brain Research and Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Pharmacology and Therapeutics, School of Medicine, Galway Neuroscience Centre, University of Galway, Galway, Ireland
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9
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Verkhratsky A, Butt A, Li B, Illes P, Zorec R, Semyanov A, Tang Y, Sofroniew MV. Astrocytes in human central nervous system diseases: a frontier for new therapies. Signal Transduct Target Ther 2023; 8:396. [PMID: 37828019 PMCID: PMC10570367 DOI: 10.1038/s41392-023-01628-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 08/15/2023] [Accepted: 08/22/2023] [Indexed: 10/14/2023] Open
Abstract
Astroglia are a broad class of neural parenchymal cells primarily dedicated to homoeostasis and defence of the central nervous system (CNS). Astroglia contribute to the pathophysiology of all neurological and neuropsychiatric disorders in ways that can be either beneficial or detrimental to disorder outcome. Pathophysiological changes in astroglia can be primary or secondary and can result in gain or loss of functions. Astroglia respond to external, non-cell autonomous signals associated with any form of CNS pathology by undergoing complex and variable changes in their structure, molecular expression, and function. In addition, internally driven, cell autonomous changes of astroglial innate properties can lead to CNS pathologies. Astroglial pathophysiology is complex, with different pathophysiological cell states and cell phenotypes that are context-specific and vary with disorder, disorder-stage, comorbidities, age, and sex. Here, we classify astroglial pathophysiology into (i) reactive astrogliosis, (ii) astroglial atrophy with loss of function, (iii) astroglial degeneration and death, and (iv) astrocytopathies characterised by aberrant forms that drive disease. We review astroglial pathophysiology across the spectrum of human CNS diseases and disorders, including neurotrauma, stroke, neuroinfection, autoimmune attack and epilepsy, as well as neurodevelopmental, neurodegenerative, metabolic and neuropsychiatric disorders. Characterising cellular and molecular mechanisms of astroglial pathophysiology represents a new frontier to identify novel therapeutic strategies.
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Affiliation(s)
- Alexei Verkhratsky
- International Joint Research Centre on Purinergic Signalling/School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania.
| | - Arthur Butt
- Institute of Biomedical and Biomolecular Sciences, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Peter Illes
- International Joint Research Centre on Purinergic Signalling/School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04109, Leipzig, Germany
| | - Robert Zorec
- Celica Biomedical, Lab Cell Engineering, Technology Park, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Alexey Semyanov
- Department of Physiology, Jiaxing University College of Medicine, 314033, Jiaxing, China
| | - Yong Tang
- International Joint Research Centre on Purinergic Signalling/School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Key Laboratory of Acupuncture for Senile Disease (Chengdu University of TCM), Ministry of Education/Acupuncture and Chronobiology Key Laboratory of Sichuan Province, Chengdu, China.
| | - Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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10
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Byvaltcev E, Behbood M, Schleimer JH, Gensch T, Semyanov A, Schreiber S, Strauss U. KCC2 reverse mode helps to clear postsynaptically released potassium at glutamatergic synapses. Cell Rep 2023; 42:112934. [PMID: 37537840 PMCID: PMC10480490 DOI: 10.1016/j.celrep.2023.112934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 08/05/2023] Open
Abstract
Extracellular potassium [K+]o elevation during synaptic activity retrogradely modifies presynaptic release and astrocytic uptake of glutamate. Hence, local K+ clearance and replenishment mechanisms are crucial regulators of glutamatergic transmission and plasticity. Based on recordings of astrocytic inward rectifier potassium current IKir and K+-sensitive electrodes as sensors of [K+]o as well as on in silico modeling, we demonstrate that the neuronal K+-Cl- co-transporter KCC2 clears local perisynaptic [K+]o during synaptic excitation by operating in an activity-dependent reversed mode. In reverse mode, KCC2 replenishes K+ in dendritic spines and complements clearance of [K+]o, therewith attenuating presynaptic glutamate release and shortening LTP. We thus demonstrate a physiological role of KCC2 in neuron-glial interactions and regulation of synaptic signaling and plasticity through the uptake of postsynaptically released K+.
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Affiliation(s)
- Egor Byvaltcev
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Mahraz Behbood
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Jan-Hendrik Schleimer
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing 1 (IBI-1, Molecular and Cellular Physiology), Forschungszentrum Jülich, Wilhem-Jonen Straße, 52428 Jülich, Germany
| | - Alexey Semyanov
- Department of Physiology, Jiaxing University College of Medicine, Zhejiang Pro, Jiaxing 314033, China
| | - Susanne Schreiber
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Ulf Strauss
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany.
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11
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Pereira MJ, Ayana R, Holt MG, Arckens L. Chemogenetic manipulation of astrocyte activity at the synapse- a gateway to manage brain disease. Front Cell Dev Biol 2023; 11:1193130. [PMID: 37534103 PMCID: PMC10393042 DOI: 10.3389/fcell.2023.1193130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 06/14/2023] [Indexed: 08/04/2023] Open
Abstract
Astrocytes are the major glial cell type in the central nervous system (CNS). Initially regarded as supportive cells, it is now recognized that this highly heterogeneous cell population is an indispensable modulator of brain development and function. Astrocytes secrete neuroactive molecules that regulate synapse formation and maturation. They also express hundreds of G protein-coupled receptors (GPCRs) that, once activated by neurotransmitters, trigger intracellular signalling pathways that can trigger the release of gliotransmitters which, in turn, modulate synaptic transmission and neuroplasticity. Considering this, it is not surprising that astrocytic dysfunction, leading to synaptic impairment, is consistently described as a factor in brain diseases, whether they emerge early or late in life due to genetic or environmental factors. Here, we provide an overview of the literature showing that activation of genetically engineered GPCRs, known as Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), to specifically modulate astrocyte activity partially mimics endogenous signalling pathways in astrocytes and improves neuronal function and behavior in normal animals and disease models. Therefore, we propose that expressing these genetically engineered GPCRs in astrocytes could be a promising strategy to explore (new) signalling pathways which can be used to manage brain disorders. The precise molecular, functional and behavioral effects of this type of manipulation, however, differ depending on the DREADD receptor used, targeted brain region and timing of the intervention, between healthy and disease conditions. This is likely a reflection of regional and disease/disease progression-associated astrocyte heterogeneity. Therefore, a thorough investigation of the effects of such astrocyte manipulation(s) must be conducted considering the specific cellular and molecular environment characteristic of each disease and disease stage before this has therapeutic applicability.
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Affiliation(s)
- Maria João Pereira
- Department of Biology, Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, Leuven, Belgium
| | - Rajagopal Ayana
- Department of Biology, Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, Leuven, Belgium
| | - Matthew G. Holt
- Instituto de Investigação e Inovação em Saúde (i3S), Laboratory of Synapse Biology, Universidade do Porto, Porto, Portugal
| | - Lutgarde Arckens
- Department of Biology, Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, Leuven, Belgium
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12
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Stogsdill JA, Harwell CC, Goldman SA. Astrocytes as master modulators of neural networks: Synaptic functions and disease-associated dysfunction of astrocytes. Ann N Y Acad Sci 2023; 1525:41-60. [PMID: 37219367 DOI: 10.1111/nyas.15004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Astrocytes are the most abundant glial cell type in the central nervous system and are essential to the development, plasticity, and maintenance of neural circuits. Astrocytes are heterogeneous, with their diversity rooted in developmental programs modulated by the local brain environment. Astrocytes play integral roles in regulating and coordinating neural activity extending far beyond their metabolic support of neurons and other brain cell phenotypes. Both gray and white matter astrocytes occupy critical functional niches capable of modulating brain physiology on time scales slower than synaptic activity but faster than those adaptive responses requiring a structural change or adaptive myelination. Given their many associations and functional roles, it is not surprising that astrocytic dysfunction has been causally implicated in a broad set of neurodegenerative and neuropsychiatric disorders. In this review, we focus on recent discoveries concerning the contributions of astrocytes to the function of neural networks, with a dual focus on the contribution of astrocytes to synaptic development and maturation, and on their role in supporting myelin integrity, and hence conduction and its regulation. We then address the emerging roles of astrocytic dysfunction in disease pathogenesis and on potential strategies for targeting these cells for therapeutic purposes.
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Affiliation(s)
| | - Corey C Harwell
- Department of Neurology, University of California San Francisco, San Francisco, California, USA
| | - Steven A Goldman
- Sana Biotechnology Inc., Cambridge, Massachusetts, USA
- Center for Translational Neuromedicine, University of Rochester, Rochester, New York, USA
- University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
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13
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Villanueva CB, Stephensen HJT, Mokso R, Benraiss A, Sporring J, Goldman SA. Astrocytic engagement of the corticostriatal synaptic cleft is disrupted in a mouse model of Huntington's disease. Proc Natl Acad Sci U S A 2023; 120:e2210719120. [PMID: 37279261 PMCID: PMC10268590 DOI: 10.1073/pnas.2210719120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 04/25/2023] [Indexed: 06/08/2023] Open
Abstract
Astroglial dysfunction contributes to the pathogenesis of Huntington's disease (HD), and glial replacement can ameliorate the disease course. To establish the topographic relationship of diseased astrocytes to medium spiny neuron (MSN) synapses in HD, we used 2-photon imaging to map the relationship of turboRFP-tagged striatal astrocytes and rabies-traced, EGFP-tagged coupled neuronal pairs in R6/2 HD and wild-type (WT) mice. The tagged, prospectively identified corticostriatal synapses were then studied by correlated light electron microscopy followed by serial block-face scanning EM, allowing nanometer-scale assessment of synaptic structure in 3D. By this means, we compared the astrocytic engagement of single striatal synapses in HD and WT brains. R6/2 HD astrocytes exhibited constricted domains, with significantly less coverage of mature dendritic spines than WT astrocytes, despite enhanced engagement of immature, thin spines. These data suggest that disease-dependent changes in the astroglial engagement and sequestration of MSN synapses enable the high synaptic and extrasynaptic levels of glutamate and K+ that underlie striatal hyperexcitability in HD. As such, these data suggest that astrocytic structural pathology may causally contribute to the synaptic dysfunction and disease phenotype of those neurodegenerative disorders characterized by network overexcitation.
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Affiliation(s)
- Carlos Benitez Villanueva
- Center for Translational Neuromedicine, University of Copenhagen, Faculty of Health and Medical Sciences, Copenhagen N2200, Denmark
| | - Hans J. T. Stephensen
- Center for Translational Neuromedicine, University of Copenhagen, Faculty of Health and Medical Sciences, Copenhagen N2200, Denmark
- Department of Computer Science, University of Copenhagen, Faculty of Science, Copenhagen N2200, Denmark
| | - Rajmund Mokso
- Faculty of Engineering, Division of Solid Mechanics, Lund University, Lund22100, Sweden
| | - Abdellatif Benraiss
- Center for Translational Neuroscience, Department of Neurology, University of Rochester Medical Center, Rochester, NY14642
| | - Jon Sporring
- Department of Computer Science, University of Copenhagen, Faculty of Science, Copenhagen N2200, Denmark
| | - Steven A. Goldman
- Center for Translational Neuromedicine, University of Copenhagen, Faculty of Health and Medical Sciences, Copenhagen N2200, Denmark
- Center for Translational Neuroscience, Department of Neurology, University of Rochester Medical Center, Rochester, NY14642
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14
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Purushotham SS, Buskila Y. Astrocytic modulation of neuronal signalling. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1205544. [PMID: 37332623 PMCID: PMC10269688 DOI: 10.3389/fnetp.2023.1205544] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/18/2023] [Indexed: 06/20/2023]
Abstract
Neuronal signalling is a key element in neuronal communication and is essential for the proper functioning of the CNS. Astrocytes, the most prominent glia in the brain play a key role in modulating neuronal signalling at the molecular, synaptic, cellular, and network levels. Over the past few decades, our knowledge about astrocytes and their functioning has evolved from considering them as merely a brain glue that provides structural support to neurons, to key communication elements. Astrocytes can regulate the activity of neurons by controlling the concentrations of ions and neurotransmitters in the extracellular milieu, as well as releasing chemicals and gliotransmitters that modulate neuronal activity. The aim of this review is to summarise the main processes through which astrocytes are modulating brain function. We will systematically distinguish between direct and indirect pathways in which astrocytes affect neuronal signalling at all levels. Lastly, we will summarize pathological conditions that arise once these signalling pathways are impaired focusing on neurodegeneration.
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Affiliation(s)
| | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- The MARCS Institute, Western Sydney University, Campbelltown, NSW, Australia
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15
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Lin SS, Zhou B, Chen BJ, Jiang RT, Li B, Illes P, Semyanov A, Tang Y, Verkhratsky A. Electroacupuncture prevents astrocyte atrophy to alleviate depression. Cell Death Dis 2023; 14:343. [PMID: 37248211 DOI: 10.1038/s41419-023-05839-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/16/2023] [Accepted: 04/26/2023] [Indexed: 05/31/2023]
Abstract
Astrocyte atrophy is the main histopathological hallmark of major depressive disorder (MDD) in humans and in animal models of depression. Here we show that electroacupuncture prevents astrocyte atrophy in the prefrontal cortex and alleviates depressive-like behaviour in mice subjected to chronic unpredictable mild stress (CUMS). Treatment of mice with CUMS induced depressive-like phenotypes as confirmed by sucrose preference test, tail suspension test, and forced swimming test. These behavioural changes were paralleled with morphological atrophy of astrocytes in the prefrontal cortex, revealed by analysis of 3D reconstructions of confocal Z-stack images of mCherry expressing astrocytes. This morphological atrophy was accompanied by a decrease in the expression of cytoskeletal linker Ezrin, associated with formation of astrocytic leaflets, which form astroglial synaptic cradle. Electroacupuncture at the acupoint ST36, as well as treatment with anti-depressant fluoxetine, prevented depressive-like behaviours, astrocytic atrophy, and down-regulation of astrocytic ezrin. In conclusion, our data further strengthen the notion of a primary role of astrocytic atrophy in depression and reveal astrocytes as cellular target for electroacupuncture in treatment of depressive disorders.
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Affiliation(s)
- Si-Si Lin
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
| | - Bin Zhou
- Laboratory of Anaesthesia and Critical Care Medicine, Department of Anaesthesiology, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Bin-Jie Chen
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Ruo-Tian Jiang
- Laboratory of Anaesthesia and Critical Care Medicine, Department of Anaesthesiology, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China
| | - Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Peter Illes
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
| | - Alexey Semyanov
- College of Medicine, Jiaxing University, Jiaxing, China
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Yong Tang
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Acupuncture and Chronobiology Key Laboratory of Sichuan Province, Chengdu, China.
| | - Alexei Verkhratsky
- International Joint Research Centre on Purinergic Signalling of Sichuan Province /Research Centre on TCM-Rehabilitation and Neural Circuit, School of Acupuncture and Tuina/Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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16
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Martínez San Segundo P, Terni B, Llobet A. Multivesicular release favors short term synaptic depression in hippocampal autapses. Front Cell Neurosci 2023; 17:1057242. [PMID: 37265578 PMCID: PMC10230035 DOI: 10.3389/fncel.2023.1057242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 04/10/2023] [Indexed: 06/03/2023] Open
Abstract
Presynaptic terminals of the central nervous system can support univesicular and multivesicular synchronous release of neurotransmitters, however, the functional implications of the prevalence of one mechanism over the other are yet unresolved. Here, we took advantage of the expression of SF-iGluSnFR.S72A in the astrocytic feeder layer of autaptic hippocampal neuronal cultures to associate the liberation of glutamate to excitatory postsynaptic currents. The presence of the glutamate sensor in glial cells avoided any interference with the function of endogenous postsynaptic receptors. It was possible to optically detect changes in neurotransmitter release probability, which was heterogeneous among synaptic boutons studied. For each neuron investigated, the liberation of neurotransmitters occurred through a predominant mechanism. The prevalence of multivesicular over univesicular release increased synaptic strength and enhanced short-term synaptic depression. These results show that the preference of hippocampal boutons to synchronously release one or more vesicles determines the strength and low pass filtering properties of the synapses established.
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Affiliation(s)
- Pablo Martínez San Segundo
- Laboratory of Neurobiology, Department of Pathology and Experimental Therapy, Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Beatrice Terni
- Laboratory of Neurobiology, Department of Pathology and Experimental Therapy, Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Artur Llobet
- Laboratory of Neurobiology, Department of Pathology and Experimental Therapy, Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
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17
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Delgado L, Navarrete M. Shining the Light on Astrocytic Ensembles. Cells 2023; 12:1253. [PMID: 37174653 PMCID: PMC10177371 DOI: 10.3390/cells12091253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
While neurons have traditionally been considered the primary players in information processing, the role of astrocytes in this mechanism has largely been overlooked due to experimental constraints. In this review, we propose that astrocytic ensembles are active working groups that contribute significantly to animal conduct and suggest that studying the maps of these ensembles in conjunction with neurons is crucial for a more comprehensive understanding of behavior. We also discuss available methods for studying astrocytes and argue that these ensembles, complementarily with neurons, code and integrate complex behaviors, potentially specializing in concrete functions.
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Affiliation(s)
| | - Marta Navarrete
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), 28002 Madrid, Spain
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18
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Khakh BS, Goldman SA. Astrocytic contributions to Huntington's disease pathophysiology. Ann N Y Acad Sci 2023; 1522:42-59. [PMID: 36864567 PMCID: PMC10145027 DOI: 10.1111/nyas.14977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Huntington's disease (HD) is a fatal, monogenic, autosomal dominant neurodegenerative disease caused by a polyglutamine-encoding CAG expansion in the huntingtin (HTT) gene that results in mutant huntingtin proteins (mHTT) in cells throughout the body. Although large parts of the central nervous system (CNS) are affected, the striatum is especially vulnerable and undergoes marked atrophy. Astrocytes are abundant within the striatum and contain mHTT in HD, as well as in mouse models of the disease. We focus on striatal astrocytes and summarize how they participate in, and contribute to, molecular pathophysiology and disease-related phenotypes in HD model mice. Where possible, reference is made to pertinent astrocyte alterations in human HD. Astrocytic dysfunctions related to cellular morphology, extracellular ion and neurotransmitter homeostasis, and metabolic support all accompany the development and progression of HD, in both transgenic mouse and human cellular and chimeric models of HD. These findings reveal the potential for the therapeutic targeting of astrocytes so as to restore synaptic as well as tissue homeostasis in HD. Elucidation of the mechanisms by which astrocytes contribute to HD pathogenesis may inform a broader understanding of the role of glial pathology in neurodegenerative disorders and, by so doing, enable new strategies of glial-directed therapeutics.
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Affiliation(s)
- Baljit S. Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Steven A. Goldman
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
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19
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Soto JS, Jami-Alahmadi Y, Chacon J, Moye SL, Diaz-Castro B, Wohlschlegel JA, Khakh BS. Astrocyte-neuron subproteomes and obsessive-compulsive disorder mechanisms. Nature 2023; 616:764-773. [PMID: 37046092 PMCID: PMC10132990 DOI: 10.1038/s41586-023-05927-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 03/07/2023] [Indexed: 04/14/2023]
Abstract
Astrocytes and neurons extensively interact in the brain. Identifying astrocyte and neuron proteomes is essential for elucidating the protein networks that dictate their respective contributions to physiology and disease. Here we used cell-specific and subcompartment-specific proximity-dependent biotinylation1 to study the proteomes of striatal astrocytes and neurons in vivo. We evaluated cytosolic and plasma membrane compartments for astrocytes and neurons to discover how these cells differ at the protein level in their signalling machinery. We also assessed subcellular compartments of astrocytes, including end feet and fine processes, to reveal their subproteomes and the molecular basis of essential astrocyte signalling and homeostatic functions. Notably, SAPAP3 (encoded by Dlgap3), which is associated with obsessive-compulsive disorder (OCD) and repetitive behaviours2-8, was detected at high levels in striatal astrocytes and was enriched within specific astrocyte subcompartments where it regulated actin cytoskeleton organization. Furthermore, genetic rescue experiments combined with behavioural analyses and molecular assessments in a mouse model of OCD4 lacking SAPAP3 revealed distinct contributions of astrocytic and neuronal SAPAP3 to repetitive and anxiety-related OCD-like phenotypes. Our data define how astrocytes and neurons differ at the protein level and in their major signalling pathways. Moreover, they reveal how astrocyte subproteomes vary between physiological subcompartments and how both astrocyte and neuronal SAPAP3 mechanisms contribute to OCD phenotypes in mice. Our data indicate that therapeutic strategies that target both astrocytes and neurons may be useful to explore in OCD and potentially other brain disorders.
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Affiliation(s)
- Joselyn S Soto
- Department of Physiology, University of California, Los Angeles, CA, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Jakelyn Chacon
- Department of Physiology, University of California, Los Angeles, CA, USA
| | - Stefanie L Moye
- Department of Physiology, University of California, Los Angeles, CA, USA
| | - Blanca Diaz-Castro
- Department of Physiology, University of California, Los Angeles, CA, USA
- UK Dementia Research Institute and Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, CA, USA.
- Department of Neurobiology, University of California, Los Angeles, CA, USA.
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20
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Villablanca C, Vidal R, Gonzalez-Billault C. Are cytoskeleton changes observed in astrocytes functionally linked to aging? Brain Res Bull 2023; 196:59-67. [PMID: 36935053 DOI: 10.1016/j.brainresbull.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/22/2023] [Accepted: 03/16/2023] [Indexed: 03/19/2023]
Abstract
Astrocytes are active participants in the performance of the Central Nervous System (CNS) in both health and disease. During aging, astrocytes are susceptible to reactive astrogliosis, a molecular state characterized by functional changes in response to pathological situations, and cellular senescence, characterized by loss of cell division, apoptosis resistance, and gain of proinflammatory functions. This results in two different states of astrocytes, which can produce proinflammatory phenotypes with harmful consequences in chronic conditions. Reactive astrocytes and senescent astrocytes share morpho-functional features that are dependent on the organization of the cytoskeleton. However, such changes in the cytoskeleton have yet to receive the necessary attention to explain their role in the alterations of astrocytes that are associated with aging and pathologies. In this review, we summarize all the available findings that connect changes in the cytoskeleton of the astrocytes with aging. In addition, we discuss future avenues that we believe will guide such a novel topic.
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Affiliation(s)
- Cristopher Villablanca
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | - René Vidal
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; Center for Integrative Biology, Universidad Mayor, Santiago, Chile; Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile; Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile; Department of Neurosciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile; Institute for Nutrition and Food Technologies, Universidad de Chile, Santiago, Chile.
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21
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Astrocyte heterogeneity and interactions with local neural circuits. Essays Biochem 2023; 67:93-106. [PMID: 36748397 PMCID: PMC10011406 DOI: 10.1042/ebc20220136] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/09/2023] [Accepted: 01/09/2023] [Indexed: 02/08/2023]
Abstract
Astrocytes are ubiquitous within the central nervous system (CNS). These cells possess many individual processes which extend out into the neuropil, where they interact with a variety of other cell types, including neurons at synapses. Astrocytes are now known to be active players in all aspects of the synaptic life cycle, including synapse formation and elimination, synapse maturation, maintenance of synaptic homeostasis and modulation of synaptic transmission. Traditionally, astrocytes have been studied as a homogeneous group of cells. However, recent studies have uncovered a surprising degree of heterogeneity in their development and function, suggesting that astrocytes may be matched to neurons to support local circuits. Hence, a better understanding of astrocyte heterogeneity and its implications are needed to understand brain function.
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22
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Liu L, Gao H, Li J, Chen S. Probing microdomain Ca 2+ activity and synaptic transmission with a node-based tripartite synapse model. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1111306. [PMID: 36926546 PMCID: PMC10013067 DOI: 10.3389/fnetp.2023.1111306] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/27/2023] [Indexed: 06/08/2023]
Abstract
Astrocytic fine processes are the most minor structures of astrocytes but host much of the Ca2+ activity. These localized Ca2+ signals spatially restricted to microdomains are crucial for information processing and synaptic transmission. However, the mechanistic link between astrocytic nanoscale processes and microdomain Ca2+ activity remains hazily understood because of the technical difficulties in accessing this structurally unresolved region. In this study, we used computational models to disentangle the intricate relations of morphology and local Ca2+ dynamics involved in astrocytic fine processes. We aimed to answer: 1) how nano-morphology affects local Ca2+ activity and synaptic transmission, 2) and how fine processes affect Ca2+ activity of large process they connect. To address these issues, we undertook the following two computational modeling: 1) we integrated the in vivo astrocyte morphological data from a recent study performed with super-resolution microscopy that discriminates sub-compartments of various shapes, referred to as nodes and shafts to a classic IP3R-mediated Ca2+ signaling framework describing the intracellular Ca2+ dynamics, 2) we proposed a node-based tripartite synapse model linking with astrocytic morphology to predict the effect of structural deficits of astrocytes on synaptic transmission. Extensive simulations provided us with several biological insights: 1) the width of nodes and shafts could strongly influence the spatiotemporal variability of Ca2+ signals properties but what indeed determined the Ca2+ activity was the width ratio between nodes and shafts, 2) the connectivity of nodes to larger processes markedly shaped the Ca2+ signal of the parent process rather than nodes morphology itself, 3) the morphological changes of astrocytic part might potentially induce the abnormality of synaptic transmission by affecting the level of glutamate at tripartite synapses. Taken together, this comprehensive model which integrated theoretical computation and in vivo morphological data highlights the role of the nanomorphology of astrocytes in signal transmission and its possible mechanisms related to pathological conditions.
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Affiliation(s)
- Langzhou Liu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Huayi Gao
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Jinyu Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Shangbin Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
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23
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Yao S, Wang Q, Hirokawa KE, Ouellette B, Ahmed R, Bomben J, Brouner K, Casal L, Caldejon S, Cho A, Dotson NI, Daigle TL, Egdorf T, Enstrom R, Gary A, Gelfand E, Gorham M, Griffin F, Gu H, Hancock N, Howard R, Kuan L, Lambert S, Lee EK, Luviano J, Mace K, Maxwell M, Mortrud MT, Naeemi M, Nayan C, Ngo NK, Nguyen T, North K, Ransford S, Ruiz A, Seid S, Swapp J, Taormina MJ, Wakeman W, Zhou T, Nicovich PR, Williford A, Potekhina L, McGraw M, Ng L, Groblewski PA, Tasic B, Mihalas S, Harris JA, Cetin A, Zeng H. A whole-brain monosynaptic input connectome to neuron classes in mouse visual cortex. Nat Neurosci 2023; 26:350-364. [PMID: 36550293 PMCID: PMC10039800 DOI: 10.1038/s41593-022-01219-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 10/27/2022] [Indexed: 12/24/2022]
Abstract
Identification of structural connections between neurons is a prerequisite to understanding brain function. Here we developed a pipeline to systematically map brain-wide monosynaptic input connections to genetically defined neuronal populations using an optimized rabies tracing system. We used mouse visual cortex as the exemplar system and revealed quantitative target-specific, layer-specific and cell-class-specific differences in its presynaptic connectomes. The retrograde connectivity indicates the presence of ventral and dorsal visual streams and further reveals topographically organized and continuously varying subnetworks mediated by different higher visual areas. The visual cortex hierarchy can be derived from intracortical feedforward and feedback pathways mediated by upper-layer and lower-layer input neurons. We also identify a new role for layer 6 neurons in mediating reciprocal interhemispheric connections. This study expands our knowledge of the visual system connectomes and demonstrates that the pipeline can be scaled up to dissect connectivity of different cell populations across the mouse brain.
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Affiliation(s)
- Shenqin Yao
- Allen Institute for Brain Science, Seattle, WA, USA.
| | - Quanxin Wang
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Karla E Hirokawa
- Allen Institute for Brain Science, Seattle, WA, USA
- Cajal Neuroscience, Seattle, WA, USA
| | | | | | | | | | - Linzy Casal
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Andy Cho
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Tom Egdorf
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Amanda Gary
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Hong Gu
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Leonard Kuan
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Kyla Mace
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | | | | | - Kat North
- Allen Institute for Brain Science, Seattle, WA, USA
- Cajal Neuroscience, Seattle, WA, USA
| | | | | | - Sam Seid
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Jackie Swapp
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Thomas Zhou
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Philip R Nicovich
- Allen Institute for Brain Science, Seattle, WA, USA
- Cajal Neuroscience, Seattle, WA, USA
| | | | | | - Medea McGraw
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Lydia Ng
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Julie A Harris
- Allen Institute for Brain Science, Seattle, WA, USA
- Cajal Neuroscience, Seattle, WA, USA
| | - Ali Cetin
- Allen Institute for Brain Science, Seattle, WA, USA
- CNC Program, Stanford University, Palo Alto, CA, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA.
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24
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Kruyer A, Kalivas PW, Scofield MD. Astrocyte regulation of synaptic signaling in psychiatric disorders. Neuropsychopharmacology 2023; 48:21-36. [PMID: 35577914 PMCID: PMC9700696 DOI: 10.1038/s41386-022-01338-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/27/2022] [Accepted: 05/01/2022] [Indexed: 02/07/2023]
Abstract
Over the last 15 years, the field of neuroscience has evolved toward recognizing the critical role of astroglia in shaping neuronal synaptic activity and along with the pre- and postsynapse is now considered an equal partner in tripartite synaptic transmission and plasticity. The relative youth of this recognition and a corresponding deficit in reagents and technologies for quantifying and manipulating astroglia relative to neurons continues to hamper advances in understanding tripartite synaptic physiology. Nonetheless, substantial advances have been made and are reviewed herein. We review the role of astroglia in synaptic function and regulation of behavior with an eye on how tripartite synapses figure into brain pathologies underlying behavioral impairments in psychiatric disorders, both from the perspective of measures in postmortem human brains and more subtle influences on tripartite synaptic regulation of behavior in animal models of psychiatric symptoms. Our goal is to provide the reader a well-referenced state-of-the-art understanding of current knowledge and predict what we may discover with deeper investigation of tripartite synapses using reagents and technologies not yet available.
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Affiliation(s)
- Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Peter W Kalivas
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA.
| | - Michael D Scofield
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
- Department of Anesthesia & Perioperative Medicine, Medical University of South Carolina, Charleston, SC, USA.
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25
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Cvetanovic M, Gray M. Contribution of Glial Cells to Polyglutamine Diseases: Observations from Patients and Mouse Models. Neurotherapeutics 2023; 20:48-66. [PMID: 37020152 PMCID: PMC10119372 DOI: 10.1007/s13311-023-01357-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2023] [Indexed: 04/07/2023] Open
Abstract
Neurodegenerative diseases are broadly characterized neuropathologically by the degeneration of vulnerable neuronal cell types in a specific brain region. The degeneration of specific cell types has informed on the various phenotypes/clinical presentations in someone suffering from these diseases. Prominent neurodegeneration of specific neurons is seen in polyglutamine expansion diseases including Huntington's disease (HD) and spinocerebellar ataxias (SCA). The clinical manifestations observed in these diseases could be as varied as the abnormalities in motor function observed in those who have Huntington's disease (HD) as demonstrated by a chorea with substantial degeneration of striatal medium spiny neurons (MSNs) or those with various forms of spinocerebellar ataxia (SCA) with an ataxic motor presentation primarily due to degeneration of cerebellar Purkinje cells. Due to the very significant nature of the degeneration of MSNs in HD and Purkinje cells in SCAs, much of the research has centered around understanding the cell autonomous mechanisms dysregulated in these neuronal cell types. However, an increasing number of studies have revealed that dysfunction in non-neuronal glial cell types contributes to the pathogenesis of these diseases. Here we explore these non-neuronal glial cell types with a focus on how each may contribute to the pathogenesis of HD and SCA and the tools used to evaluate glial cells in the context of these diseases. Understanding the regulation of supportive and harmful phenotypes of glia in disease could lead to development of novel glia-focused neurotherapeutics.
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Affiliation(s)
- Marija Cvetanovic
- Department of Neuroscience, Institute for Translational Neuroscience, University of Minnesota, Minneapolis, USA
| | - Michelle Gray
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL, USA.
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26
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Iwata K, Ferdousi F, Arai Y, Isoda H. Interactions between Major Bioactive Polyphenols of Sugarcane Top: Effects on Human Neural Stem Cell Differentiation and Astrocytic Maturation. Int J Mol Sci 2022; 23:ijms232315120. [PMID: 36499441 PMCID: PMC9738893 DOI: 10.3390/ijms232315120] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Sugarcane (Saccharum officinarum L.) is a tropical plant grown for sugar production. We recently showed that sugarcane top (ST) ameliorates cognitive decline in a mouse model of accelerated aging via promoting neuronal differentiation and neuronal energy metabolism and extending the length of the astrocytic process in vitro. Since the crude extract consists of multicomponent mixtures, it is crucial to identify bioactive compounds of interest and the affected molecular targets. In the present study, we investigated the bioactivities of major polyphenols of ST, namely 3-O-caffeoylquinic acid (3CQA), 5-O-caffeoylquinic acid (5CQA), 3-O-feruloylquinic acid (3FQA), and Isoorientin (ISO), in human fetal neural stem cells (hNSCs)- an in vitro model system for studying neural development. We found that multiple polyphenols of ST contributed synergistically to stimulate neuronal differentiation of hNSCs and induce mitochondrial activity in immature astrocytes. Mono-CQAs (3CQA and 5CQA) regulated the expression of cyclins related to G1 cell cycle arrest, whereas ISO regulated basic helix-loop-helix transcription factors related to cell fate determination. Additionally, mono-CQAs activated p38 and ISO inactivated GSK3β. In hNSC-derived immature astrocytes, the compounds upregulated mRNA expression of PGC-1α, a master regulator of astrocytic mitochondrial biogenesis. Altogether, our findings suggest that synergistic interactions between major polyphenols of ST contribute to its potential for neuronal differentiation and astrocytic maturation.
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Affiliation(s)
- Kengo Iwata
- School of Integrative and Global Majors, University of Tsukuba, Tsukuba 305-8572, Japan
- Nipoo Co., Ltd., Osaka 574-0062, Japan
| | - Farhana Ferdousi
- Alliance for Research on the Mediterranean and North Africa (ARENA), University of Tsukuba, Tsukuba 305-8572, Japan
- AIST—University of Tsukuba Open Innovation Laboratory for Food and Medicinal Resource Engineering (FoodMed-OIL), Tsukuba 305-8572, Japan
| | | | - Hiroko Isoda
- School of Integrative and Global Majors, University of Tsukuba, Tsukuba 305-8572, Japan
- Alliance for Research on the Mediterranean and North Africa (ARENA), University of Tsukuba, Tsukuba 305-8572, Japan
- AIST—University of Tsukuba Open Innovation Laboratory for Food and Medicinal Resource Engineering (FoodMed-OIL), Tsukuba 305-8572, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
- Correspondence: ; Tel.: +81-29-853-5775
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27
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Endo F, Kasai A, Soto JS, Yu X, Qu Z, Hashimoto H, Gradinaru V, Kawaguchi R, Khakh BS. Molecular basis of astrocyte diversity and morphology across the CNS in health and disease. Science 2022; 378:eadc9020. [PMID: 36378959 PMCID: PMC9873482 DOI: 10.1126/science.adc9020] [Citation(s) in RCA: 125] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Astrocytes, a type of glia, are abundant and morphologically complex cells. Here, we report astrocyte molecular profiles, diversity, and morphology across the mouse central nervous system (CNS). We identified shared and region-specific astrocytic genes and functions and explored the cellular origins of their regional diversity. We identified gene networks correlated with astrocyte morphology, several of which unexpectedly contained Alzheimer's disease (AD) risk genes. CRISPR/Cas9-mediated reduction of candidate genes reduced astrocyte morphological complexity and resulted in cognitive deficits. The same genes were down-regulated in human AD, in an AD mouse model that displayed reduced astrocyte morphology, and in other human brain disorders. We thus provide comprehensive molecular data on astrocyte diversity and mechanisms across the CNS and on the molecular basis of astrocyte morphology in health and disease.
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Affiliation(s)
- Fumito Endo
- Department of Physiology, University of California Los Angeles; Los Angeles USA
| | - Atsushi Kasai
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University; Suita, Osaka, Japan
| | - Joselyn S. Soto
- Department of Physiology, University of California Los Angeles; Los Angeles USA
| | - Xinzhu Yu
- Department of Physiology, University of California Los Angeles; Los Angeles USA
| | - Zhe Qu
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, USA
| | - Hitoshi Hashimoto
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University; Suita, Osaka, Japan,Molecular Research Center for Children’s Mental Development, United Graduate School of Child Development, Osaka University; Suita, Osaka, Japan,Division of Bioscience, Institute for Datability Science, Osaka University; Suita, Osaka, Japan.,Open and Transdisciplinary Research Initiatives, Osaka University; Suita, Osaka, Japan,Department of Molecular Pharmaceutical Science, Graduate School of Medicine, Osaka University; Suita, Osaka, Japan
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, USA
| | - Riki Kawaguchi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles; Los Angeles USA
| | - Baljit S. Khakh
- Department of Physiology, University of California Los Angeles; Los Angeles USA,Department of Neurobiology, University of California Los Angeles; Los Angeles USA,Corresponding author.
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28
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Badia-Soteras A, Heistek TS, Kater MSJ, Mak A, Negrean A, van den Oever MC, Mansvelder HD, Khakh BS, Min R, Smit AB, Verheijen MHG. Retraction of Astrocyte Leaflets From the Synapse Enhances Fear Memory. Biol Psychiatry 2022:S0006-3223(22)01705-X. [PMID: 36702661 DOI: 10.1016/j.biopsych.2022.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 10/07/2022] [Accepted: 10/20/2022] [Indexed: 01/28/2023]
Abstract
BACKGROUND The formation and retrieval of fear memories depends on orchestrated synaptic activity of neuronal ensembles within the hippocampus, and it is becoming increasingly evident that astrocytes residing in the environment of these synapses play a central role in shaping cellular memory representations. Astrocyte distal processes, known as leaflets, fine-tune synaptic activity by clearing neurotransmitters and limiting glutamate diffusion. However, how astroglial synaptic coverage contributes to mnemonic processing of fearful experiences remains largely unknown. METHODS We used electron microscopy to observe changes in astroglial coverage of hippocampal synapses during consolidation of fear memory in mice. To manipulate astroglial synaptic coverage, we depleted ezrin, an integral leaflet-structural protein, from hippocampal astrocytes using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 gene editing. Next, a combination of Föster resonance energy transfer analysis, genetically encoded glutamate sensors, and whole-cell patch-clamp recordings was used to determine whether the proximity of astrocyte leaflets to the synapse is critical for synaptic integrity and function. RESULTS We found that consolidation of a recent fear memory is accompanied by a transient retraction of astrocyte leaflets from hippocampal synapses and increased activation of NMDA receptors. Accordingly, astrocyte-specific depletion of ezrin resulted in shorter astrocyte leaflets and reduced astrocyte contact with the synaptic cleft, which consequently boosted extrasynaptic glutamate diffusion and NMDA receptor activation. Importantly, after fear conditioning, these cellular phenotypes translated to increased retrieval-evoked activation of CA1 pyramidal neurons and enhanced fear memory expression. CONCLUSIONS Together, our data show that withdrawal of astrocyte leaflets from the synaptic cleft is an experience-induced, temporally regulated process that gates the strength of fear memories.
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Affiliation(s)
- Aina Badia-Soteras
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Tim S Heistek
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Mandy S J Kater
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Aline Mak
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Adrian Negrean
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Rogier Min
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Mark H G Verheijen
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
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29
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Kruyer A. Astrocyte Heterogeneity in Regulation of Synaptic Activity. Cells 2022; 11:cells11193135. [PMID: 36231097 PMCID: PMC9562199 DOI: 10.3390/cells11193135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/02/2022] [Accepted: 10/02/2022] [Indexed: 02/07/2023] Open
Abstract
Our awareness of the number of synapse regulatory functions performed by astroglia is rapidly expanding, raising interesting questions regarding astrocyte heterogeneity and specialization across brain regions. Whether all astrocytes are poised to signal in a multitude of ways, or are instead tuned to surrounding synapses and how astroglial signaling is altered in psychiatric and cognitive disorders are fundamental questions for the field. In recent years, molecular and morphological characterization of astroglial types has broadened our ability to design studies to better analyze and manipulate specific functions of astroglia. Recent data emerging from these studies will be discussed in depth in this review. I also highlight remaining questions emerging from new techniques recently applied toward understanding the roles of astrocytes in synapse regulation in the adult brain.
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Affiliation(s)
- Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
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30
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Schober AL, Wicki-Stordeur LE, Murai KK, Swayne LA. Foundations and implications of astrocyte heterogeneity during brain development and disease. Trends Neurosci 2022; 45:692-703. [PMID: 35879116 DOI: 10.1016/j.tins.2022.06.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/25/2022] [Accepted: 06/29/2022] [Indexed: 11/25/2022]
Abstract
Astrocytes play crucial roles in regulating brain circuit formation and physiology. Recent technological advances have revealed unprecedented levels of astrocyte diversity encompassing molecular, morphological, and functional differences. This diversification is initiated during embryonic specification events and (in rodents) continues into the early postnatal period where it overlaps with peak synapse development and circuit refinement. In fact, several lines of evidence suggest astrocyte diversity both influences and is a consequence of molecular crosstalk among developing astrocytes and other cell types, notably neurons and their synapses. Neurological disease states exhibit additional layers of astrocyte heterogeneity, which could help shed light on these cells' key pathological roles. This review highlights recent advances in clarifying astrocyte heterogeneity and molecular/cellular crosstalk and identifies key outstanding questions.
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Affiliation(s)
- Alexandra L Schober
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| | | | - Keith K Murai
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada; Quantitative Life Sciences Graduate Program, McGill University, Montreal, QC, Canada
| | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
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31
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Abdelfattah AS, Ahuja S, Akkin T, Allu SR, Brake J, Boas DA, Buckley EM, Campbell RE, Chen AI, Cheng X, Čižmár T, Costantini I, De Vittorio M, Devor A, Doran PR, El Khatib M, Emiliani V, Fomin-Thunemann N, Fainman Y, Fernandez-Alfonso T, Ferri CGL, Gilad A, Han X, Harris A, Hillman EMC, Hochgeschwender U, Holt MG, Ji N, Kılıç K, Lake EMR, Li L, Li T, Mächler P, Miller EW, Mesquita RC, Nadella KMNS, Nägerl UV, Nasu Y, Nimmerjahn A, Ondráčková P, Pavone FS, Perez Campos C, Peterka DS, Pisano F, Pisanello F, Puppo F, Sabatini BL, Sadegh S, Sakadzic S, Shoham S, Shroff SN, Silver RA, Sims RR, Smith SL, Srinivasan VJ, Thunemann M, Tian L, Tian L, Troxler T, Valera A, Vaziri A, Vinogradov SA, Vitale F, Wang LV, Uhlířová H, Xu C, Yang C, Yang MH, Yellen G, Yizhar O, Zhao Y. Neurophotonic tools for microscopic measurements and manipulation: status report. NEUROPHOTONICS 2022; 9:013001. [PMID: 35493335 PMCID: PMC9047450 DOI: 10.1117/1.nph.9.s1.013001] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Neurophotonics was launched in 2014 coinciding with the launch of the BRAIN Initiative focused on development of technologies for advancement of neuroscience. For the last seven years, Neurophotonics' agenda has been well aligned with this focus on neurotechnologies featuring new optical methods and tools applicable to brain studies. While the BRAIN Initiative 2.0 is pivoting towards applications of these novel tools in the quest to understand the brain, this status report reviews an extensive and diverse toolkit of novel methods to explore brain function that have emerged from the BRAIN Initiative and related large-scale efforts for measurement and manipulation of brain structure and function. Here, we focus on neurophotonic tools mostly applicable to animal studies. A companion report, scheduled to appear later this year, will cover diffuse optical imaging methods applicable to noninvasive human studies. For each domain, we outline the current state-of-the-art of the respective technologies, identify the areas where innovation is needed, and provide an outlook for the future directions.
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Affiliation(s)
- Ahmed S. Abdelfattah
- Brown University, Department of Neuroscience, Providence, Rhode Island, United States
| | - Sapna Ahuja
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Taner Akkin
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, Minnesota, United States
| | - Srinivasa Rao Allu
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Joshua Brake
- Harvey Mudd College, Department of Engineering, Claremont, California, United States
| | - David A. Boas
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Erin M. Buckley
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
- Emory University, Department of Pediatrics, Atlanta, Georgia, United States
| | - Robert E. Campbell
- University of Tokyo, Department of Chemistry, Tokyo, Japan
- University of Alberta, Department of Chemistry, Edmonton, Alberta, Canada
| | - Anderson I. Chen
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Xiaojun Cheng
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Tomáš Čižmár
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Irene Costantini
- University of Florence, European Laboratory for Non-Linear Spectroscopy, Department of Biology, Florence, Italy
- National Institute of Optics, National Research Council, Rome, Italy
| | - Massimo De Vittorio
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Anna Devor
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Patrick R. Doran
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Mirna El Khatib
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | | | - Natalie Fomin-Thunemann
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Yeshaiahu Fainman
- University of California San Diego, Department of Electrical and Computer Engineering, La Jolla, California, United States
| | - Tomas Fernandez-Alfonso
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Christopher G. L. Ferri
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Ariel Gilad
- The Hebrew University of Jerusalem, Institute for Medical Research Israel–Canada, Department of Medical Neurobiology, Faculty of Medicine, Jerusalem, Israel
| | - Xue Han
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Andrew Harris
- Weizmann Institute of Science, Department of Brain Sciences, Rehovot, Israel
| | | | - Ute Hochgeschwender
- Central Michigan University, Department of Neuroscience, Mount Pleasant, Michigan, United States
| | - Matthew G. Holt
- University of Porto, Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal
| | - Na Ji
- University of California Berkeley, Department of Physics, Berkeley, California, United States
| | - Kıvılcım Kılıç
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Evelyn M. R. Lake
- Yale School of Medicine, Department of Radiology and Biomedical Imaging, New Haven, Connecticut, United States
| | - Lei Li
- California Institute of Technology, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, Pasadena, California, United States
| | - Tianqi Li
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, Minnesota, United States
| | - Philipp Mächler
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Evan W. Miller
- University of California Berkeley, Departments of Chemistry and Molecular & Cell Biology and Helen Wills Neuroscience Institute, Berkeley, California, United States
| | | | | | - U. Valentin Nägerl
- Interdisciplinary Institute for Neuroscience University of Bordeaux & CNRS, Bordeaux, France
| | - Yusuke Nasu
- University of Tokyo, Department of Chemistry, Tokyo, Japan
| | - Axel Nimmerjahn
- Salk Institute for Biological Studies, Waitt Advanced Biophotonics Center, La Jolla, California, United States
| | - Petra Ondráčková
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Francesco S. Pavone
- National Institute of Optics, National Research Council, Rome, Italy
- University of Florence, European Laboratory for Non-Linear Spectroscopy, Department of Physics, Florence, Italy
| | - Citlali Perez Campos
- Columbia University, Zuckerman Mind Brain Behavior Institute, New York, United States
| | - Darcy S. Peterka
- Columbia University, Zuckerman Mind Brain Behavior Institute, New York, United States
| | - Filippo Pisano
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Ferruccio Pisanello
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Francesca Puppo
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Bernardo L. Sabatini
- Harvard Medical School, Howard Hughes Medical Institute, Department of Neurobiology, Boston, Massachusetts, United States
| | - Sanaz Sadegh
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Sava Sakadzic
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Shy Shoham
- New York University Grossman School of Medicine, Tech4Health and Neuroscience Institutes, New York, New York, United States
| | - Sanaya N. Shroff
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - R. Angus Silver
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Ruth R. Sims
- Sorbonne University, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Spencer L. Smith
- University of California Santa Barbara, Department of Electrical and Computer Engineering, Santa Barbara, California, United States
| | - Vivek J. Srinivasan
- New York University Langone Health, Departments of Ophthalmology and Radiology, New York, New York, United States
| | - Martin Thunemann
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Lei Tian
- Boston University, Departments of Electrical Engineering and Biomedical Engineering, Boston, Massachusetts, United States
| | - Lin Tian
- University of California Davis, Department of Biochemistry and Molecular Medicine, Davis, California, United States
| | - Thomas Troxler
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Antoine Valera
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Alipasha Vaziri
- Rockefeller University, Laboratory of Neurotechnology and Biophysics, New York, New York, United States
- The Rockefeller University, The Kavli Neural Systems Institute, New York, New York, United States
| | - Sergei A. Vinogradov
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Flavia Vitale
- Center for Neuroengineering and Therapeutics, Departments of Neurology, Bioengineering, Physical Medicine and Rehabilitation, Philadelphia, Pennsylvania, United States
| | - Lihong V. Wang
- California Institute of Technology, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, Pasadena, California, United States
| | - Hana Uhlířová
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Chris Xu
- Cornell University, School of Applied and Engineering Physics, Ithaca, New York, United States
| | - Changhuei Yang
- California Institute of Technology, Departments of Electrical Engineering, Bioengineering and Medical Engineering, Pasadena, California, United States
| | - Mu-Han Yang
- University of California San Diego, Department of Electrical and Computer Engineering, La Jolla, California, United States
| | - Gary Yellen
- Harvard Medical School, Department of Neurobiology, Boston, Massachusetts, United States
| | - Ofer Yizhar
- Weizmann Institute of Science, Department of Brain Sciences, Rehovot, Israel
| | - Yongxin Zhao
- Carnegie Mellon University, Department of Biological Sciences, Pittsburgh, Pennsylvania, United States
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Hodebourg R, Kalivas PW, Kruyer A. Extrasynaptic therapeutic targets in substance use and stress disorders. Trends Pharmacol Sci 2022; 43:56-68. [PMID: 34753604 PMCID: PMC8688303 DOI: 10.1016/j.tips.2021.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 10/05/2021] [Accepted: 10/08/2021] [Indexed: 01/03/2023]
Abstract
Treatments for substance use and stress disorders are based on ameliorating behavioral symptoms, not on reversing the synaptic pathology that has the potential to cure disorders. This failing arises in part from a research focus on how pre- and postsynaptic physiology is changed even though key neuropathology exists in the perisynaptic neuropil that homeostatically regulates synaptic transmission. We explore recent findings from the substance use and stress disorder literature pointing to a key role for perisynaptic astroglia and signaling in the extracellular matrix (ECM) in regulating synaptic pathology. We conclude that drugs and stress initiate long-lasting changes in brain synapses via enduring neuroadaptations in astroglia and the ECM, and that modulating extrasynaptic regulators may be therapeutically useful.
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Affiliation(s)
- Ritchy Hodebourg
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29464, USA
| | - Peter W Kalivas
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29464, USA.
| | - Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29464, USA
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33
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Abstract
Drug addiction remains a key biomedical challenge facing current neuroscience research. In addition to neural mechanisms, the focus of the vast majority of studies to date, astrocytes have been increasingly recognized as an "accomplice." According to the tripartite synapse model, astrocytes critically regulate nearby pre- and postsynaptic neuronal substrates to craft experience-dependent synaptic plasticity, including synapse formation and elimination. Astrocytes within brain regions that are implicated in drug addiction exhibit dynamic changes in activity upon exposure to cocaine and subsequently undergo adaptive changes themselves during chronic drug exposure. Recent results have identified several key astrocytic signaling pathways that are involved in cocaine-induced synaptic and circuit adaptations. In this review, we provide a brief overview of the role of astrocytes in regulating synaptic transmission and neuronal function, and discuss how cocaine influences these astrocyte-mediated mechanisms to induce persistent synaptic and circuit alterations that promote cocaine seeking and relapse. We also consider the therapeutic potential of targeting astrocytic substrates to ameliorate drug-induced neuroplasticity for behavioral benefits. While primarily focusing on cocaine-induced astrocytic responses, we also include brief discussion of other drugs of abuse where data are available.
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Tworig JM, Coate C, Feller MB. Excitatory neurotransmission activates compartmentalized calcium transients in Müller glia without affecting lateral process motility. eLife 2021; 10:73202. [PMID: 34913435 PMCID: PMC8806189 DOI: 10.7554/elife.73202] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Neural activity has been implicated in the motility and outgrowth of glial cell processes throughout the central nervous system. Here, we explore this phenomenon in Müller glia, which are specialized radial astroglia that are the predominant glial type of the vertebrate retina. Müller glia extend fine filopodia-like processes into retinal synaptic layers, in similar fashion to brain astrocytes and radial glia that exhibit perisynaptic processes. Using two-photon volumetric imaging, we found that during the second postnatal week, Müller glial processes were highly dynamic, with rapid extensions and retractions that were mediated by cytoskeletal rearrangements. During this same stage of development, retinal waves led to increases in cytosolic calcium within Müller glial lateral processes and stalks. These regions comprised distinct calcium compartments, distinguished by variable participation in waves, timing, and sensitivity to an M1 muscarinic acetylcholine receptor antagonist. However, we found that motility of lateral processes was unaffected by the presence of pharmacological agents that enhanced or blocked wave-associated calcium transients. Finally, we found that mice lacking normal cholinergic waves in the first postnatal week also exhibited normal Müller glial process morphology. Hence, outgrowth of Müller glial lateral processes into synaptic layers is determined by factors that are independent of neuronal activity. When it comes to studying the nervous system, neurons often steal the limelight; yet, they can only work properly thanks to an ensemble cast of cell types whose roles are only just emerging. For example, ‘glial cells’ – their name derives from the Greek word for glue – were once thought to play only a passive, supporting function in nervous tissues. Now, growing evidence shows that they are, in fact, integrated into neural circuits: their activity is influenced by neurons, and, in turn, they help neurons to function properly. The role of glial cells is becoming clear in the retina, the thin, light-sensitive layer that lines the back of the eye and relays visual information to the brain. There, beautifully intricate Müller glial cells display fine protrusions (or ‘processes') that intermingle with synapses, the busy space between neurons where chemical messengers are exchanged. These messengers can act on Müller cells, triggering cascades of molecular events that may influence the structure and function of glia. This is of particular interest during development: as Müller cells mature, they are exposed to chemicals released by more fully formed retinal neurons. Tworig et al. explored how neuronal messengers can influence the way Müller cells grow their processes. To do so, they tracked mouse retinal glial cells ‘live’ during development, showing that they were growing fine, highly dynamic processes in a region rich in synapses just as neurons and glia increased their communication. However, using drugs to disrupt this messaging for a short period did not seem to impact how the processes grew. Extending the blockade over a longer timeframe also did not change the way Müller cells developed, with the cells still acquiring their characteristic elaborate process networks. Taken together, these results suggest that the structural maturation of Müller glial cells is not impacted by neuronal signaling, giving a more refined understanding of how glia form in the retina and potentially in the brain.
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Affiliation(s)
- Joshua M Tworig
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Chandler Coate
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Marla B Feller
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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Abstract
Astroglia are key regulators of synaptic function, playing central roles in homeostatic ion buffering, energy dynamics, transmitter uptake, maintenance of neurotransmitter pools, and regulation of synaptic plasticity through release of neuroactive chemicals. Given the myriad of crucial homeostatic and signaling functions attributed to astrocytes and the variety of neurotransmitter receptors expressed by astroglia, they serve as prime cellular candidates for establishing maladaptive synaptic plasticity following drug exposure. Initial studies on astroglia and addiction have placed drug-mediated disruptions in the homeostatic regulation of glutamate as a central aspect of relapse vulnerability. However, the generation of sophisticated tools to study and manipulate astroglia have proven that the interaction between addictive substances, astroglia, and relapse-relevant synaptic plasticity extends far beyond the homeostatic regulation of glutamate. Here we present astroglial systems impacted by drug exposure and discuss how changes in astroglial biology contribute to addiction biology.
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36
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Poelzing S, Weinberg SH, Keener JP. Initiation and entrainment of multicellular automaticity via diffusion limited extracellular domains. Biophys J 2021; 120:5279-5294. [PMID: 34757078 DOI: 10.1016/j.bpj.2021.10.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 09/12/2021] [Accepted: 10/26/2021] [Indexed: 01/07/2023] Open
Abstract
Electrically excitable cells often spontaneously and synchronously depolarize in vitro and in vivo preparations. It remains unclear how cells entrain and autorhythmically activate above the intrinsic mean activation frequency of isolated cells with or without pacemaking mechanisms. Recent studies suggest that cyclic ion accumulation and depletion in diffusion-limited extracellular volumes modulate electrophysiology by ephaptic mechanisms (nongap junction or synaptic coupling). This report explores how potassium accumulation and depletion in a restricted extracellular domain induces spontaneous action potentials in two different computational models of excitable cells without gap junctional coupling: Hodgkin-Huxley and Luo-Rudy. Importantly, neither model will spontaneously activate on its own without external stimuli. Simulations demonstrate that cells sharing a diffusion-limited extracellular compartment can become autorhythmic and entrained despite intercellular electrical heterogeneity. Autorhythmic frequency is modulated by the cleft volume and potassium fluxes through the cleft. Additionally, inexcitable cells can suppress or induce autorhythmic activity in an excitable cell via a shared cleft. Diffusion-limited shared clefts can also entrain repolarization. Critically, this model predicts a mechanism by which diffusion-limited shared clefts can initiate, entrain, and modulate multicellular automaticity in the absence of gap junctions.
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Affiliation(s)
- Steven Poelzing
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Heart and Reparative Medicine, and the Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Roanoke, Virginia.
| | - Seth H Weinberg
- Department of Biomedical Engineering, Davis Heart and Lung Research Institute, and the Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - James P Keener
- Department of Mathematics, University of Utah, Salt Lake City, Utah
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Aryal SP, Neupane KR, Masud AA, Richards CI. Characterization of Astrocyte Morphology and Function Using a Fast and Reliable Tissue Clearing Technique. Curr Protoc 2021; 1:e279. [PMID: 34694747 PMCID: PMC8550103 DOI: 10.1002/cpz1.279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Astrocytic processes interact with synapses throughout the brain modulating neurotransmitter signaling and synaptic communication. During conditions such as exposure to drugs of abuse and neurological diseases, astrocytes respond by altering their morphological and functional properties. Reactive astrocyte phenotypes exhibit a bushy morphology with altered soma volume and an increased number of processes compared to resting astrocytes. The reactive astrocytic phenotype also overexpresses proteins one of which can be glial fibrillary acidic protein (GFAP). Fluorescence microscopy on thin tissue sections (<20 µm) requires reconstruction, often through multiple sections, to delineate the full astrocytic morphology. In contrast, tissue clearing methods have been developed that enable imaging of larger sections including the whole brain, providing an opportunity to see in-depth changes in single cell structure. In this article, a detailed protocol for studying astrocyte morphology using tissue clearing and subsequent imaging of whole brains as well as region-specific slices is provided. This method is ideal for understanding the effect of different physiological conditions on astrocyte morphology. A standard biochemistry laboratory has the resources to accomplish tissue clearing using this protocol and most universities have the required imaging facilities. Protocols to study brains from both genetically modified mice that contain an astrocyte-specific marker and from wild-type mice using antibody labeling steps after tissue clearing are provided. We also describe general protocols to conduct fluorescence imaging of astrocytes in cleared tissue to characterize their morphology. This protocol could be useful for researchers working in the rapidly growing field of astrocyte biology. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Brain perfusion, fixation, and tissue clearing Alternate Protocol: Clearing brain tissue with passive clarity Basic Protocol 2: Antibody labeling and refractive index matching Basic Protocol 3: Fluorescence imaging and characterization of astrocyte morphology.
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Affiliation(s)
- Surya P Aryal
- Department of Chemistry, University of Kentucky, Lexington, KY, USA
| | - Khaga R Neupane
- Department of Chemistry, University of Kentucky, Lexington, KY, USA
| | - Abdullah A Masud
- Department of Chemistry, University of Kentucky, Lexington, KY, USA
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Nagai J, Bellafard A, Qu Z, Yu X, Ollivier M, Gangwani MR, Diaz-Castro B, Coppola G, Schumacher SM, Golshani P, Gradinaru V, Khakh BS. Specific and behaviorally consequential astrocyte G q GPCR signaling attenuation in vivo with iβARK. Neuron 2021; 109:2256-2274.e9. [PMID: 34139149 PMCID: PMC8418870 DOI: 10.1016/j.neuron.2021.05.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/14/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022]
Abstract
Astrocytes respond to neurotransmitters and neuromodulators using G-protein-coupled receptors (GPCRs) to mediate physiological responses. Despite their importance, there has been no method to genetically, specifically, and effectively attenuate astrocyte Gq GPCR pathways to explore consequences of this prevalent signaling mechanism in vivo. We report a 122-residue inhibitory peptide from β-adrenergic receptor kinase 1 (iβARK; and inactive D110A control) to attenuate astrocyte Gq GPCR signaling. iβARK significantly attenuated Gq GPCR Ca2+ signaling in brain slices and, in vivo, altered behavioral responses, spared other GPCR responses, and did not alter astrocyte spontaneous Ca2+ signals, morphology, electrophysiological properties, or gene expression in the striatum. Furthermore, brain-wide attenuation of astrocyte Gq GPCR signaling with iβARK using PHP.eB adeno-associated viruses (AAVs), when combined with c-Fos mapping, suggested nuclei-specific contributions to behavioral adaptation and spatial memory. iβARK extends the toolkit needed to explore functions of astrocyte Gq GPCR signaling within neural circuits in vivo.
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Affiliation(s)
- Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; RIKEN Center for Brain Science, 2-1 Hirosawa Wako City, Saitama 351-0198, Japan
| | - Arash Bellafard
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Zhe Qu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 514 Burrill Hall, 407 S. Goodwin Ave, Urbana, IL 61801, USA
| | - Matthias Ollivier
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Mohitkumar R Gangwani
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Blanca Diaz-Castro
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Sarah M Schumacher
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; West LA Veterans Affairs Medical Center, Los Angeles, CA 90073, USA; Intellectual and Developmental Disabilities Research Center, Los Angeles, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, University of California, David Geffen School of Medicine, Los Angeles, Los Angeles, CA 90095-1751, USA.
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39
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Refaeli R, Doron A, Benmelech-Chovav A, Groysman M, Kreisel T, Loewenstein Y, Goshen I. Features of hippocampal astrocytic domains and their spatial relation to excitatory and inhibitory neurons. Glia 2021; 69:2378-2390. [PMID: 34117643 DOI: 10.1002/glia.24044] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 11/07/2022]
Abstract
The mounting evidence for the involvement of astrocytes in neuronal circuits function and behavior stands in stark contrast to the lack of detailed anatomical description of these cells and the neurons in their domains. To fill this void, we imaged >30,000 astrocytes in hippocampi made transparent by CLARITY, and determined the elaborate structure, distribution, and neuronal content of astrocytic domains. First, we characterized the spatial distribution of >19,000 astrocytes across CA1 lamina, and analyzed the morphology of thousands of reconstructed domains. We then determined the excitatory somatic content of CA1 astrocytes, and measured the distance between inhibitory neuronal somata to the nearest astrocyte soma. We find that on average, there are almost 14 pyramidal neurons per domain in the CA1, increasing toward the pyramidal layer midline, compared to only five excitatory neurons per domain in the amygdala. Finally, we discovered that somatostatin neurons are found in close proximity to astrocytes, compared to parvalbumin and VIP inhibitory neurons. This work provides a comprehensive large-scale quantitative foundation for studying neuron-astrocyte interactions.
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Affiliation(s)
- Ron Refaeli
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adi Doron
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aviya Benmelech-Chovav
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maya Groysman
- ELSC Vector Core Facility, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tirzah Kreisel
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yonatan Loewenstein
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel.,Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Federmann Center for the Study of Rationality, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Inbal Goshen
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
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40
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Minge D, Domingos C, Unichenko P, Behringer C, Pauletti A, Anders S, Herde MK, Delekate A, Gulakova P, Schoch S, Petzold GC, Henneberger C. Heterogeneity and Development of Fine Astrocyte Morphology Captured by Diffraction-Limited Microscopy. Front Cell Neurosci 2021; 15:669280. [PMID: 34149361 PMCID: PMC8211899 DOI: 10.3389/fncel.2021.669280] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 05/06/2021] [Indexed: 12/26/2022] Open
Abstract
The fine processes of single astrocytes can contact many thousands of synapses whose function they can modulate through bi-directional signaling. The spatial arrangement of astrocytic processes and neuronal structures is relevant for such interactions and for the support of neuronal signaling by astrocytes. At the same time, the geometry of perisynaptic astrocyte processes is variable and dynamically regulated. Studying these fine astrocyte processes represents a technical challenge, because many of them cannot be fully resolved by diffraction-limited microscopy. Therefore, we have established two indirect parameters of astrocyte morphology, which, while not fully resolving local geometry by design, provide statistical measures of astrocyte morphology: the fraction of tissue volume that astrocytes occupy and the density of resolvable astrocytic processes. Both are straightforward to obtain using widely available microscopy techniques. We here present the approach and demonstrate its robustness across various experimental conditions using mainly two-photon excitation fluorescence microscopy in acute slices and in vivo as well as modeling. Using these indirect measures allowed us to analyze the morphology of relatively large populations of astrocytes. Doing so we captured the heterogeneity of astrocytes within and between the layers of the hippocampal CA1 region and the developmental profile of astrocyte morphology. This demonstrates that volume fraction (VF) and segment density are useful parameters for describing the structure of astrocytes. They are also suitable for online monitoring of astrocyte morphology with widely available microscopy techniques.
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Affiliation(s)
- Daniel Minge
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Cátia Domingos
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Petr Unichenko
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Charlotte Behringer
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Alberto Pauletti
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Stefanie Anders
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Michel K Herde
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Andrea Delekate
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Polina Gulakova
- Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Susanne Schoch
- Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Division of Vascular Neurology, University Hospital Bonn, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Institute of Neurology, University College London, London, United Kingdom
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41
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Sancho L, Contreras M, Allen NJ. Glia as sculptors of synaptic plasticity. Neurosci Res 2021; 167:17-29. [PMID: 33316304 PMCID: PMC8513541 DOI: 10.1016/j.neures.2020.11.005] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022]
Abstract
Glial cells are non-neuronal cells in the nervous system that are crucial for proper brain development and function. Three major classes of glia in the central nervous system (CNS) include astrocytes, microglia and oligodendrocytes. These cells have dynamic morphological and functional properties and constantly surveil neural activity throughout life, sculpting synaptic plasticity. Astrocytes form part of the tripartite synapse with neurons and perform many homeostatic functions essential to proper synaptic function including clearing neurotransmitter and regulating ion balance; they can modify these properties, in addition to additional mechanisms such as gliotransmitter release, to influence short- and long-term plasticity. Microglia, the resident macrophage of the CNS, monitor synaptic activity and can eliminate synapses by phagocytosis or modify synapses by release of cytokines or neurotrophic factors. Oligodendrocytes regulate speed of action potential conduction and efficiency of information exchange through the formation of myelin, having important consequences for the plasticity of neural circuits. A deeper understanding of how glia modulate synaptic and circuit plasticity will further our understanding of the ongoing changes that take place throughout life in the dynamic environment of the CNS.
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Affiliation(s)
- Laura Sancho
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Minerva Contreras
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Nicola J Allen
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA, 92037, USA.
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42
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Yu X, Moye SL, Khakh BS. Local and CNS-Wide Astrocyte Intracellular Calcium Signaling Attenuation In Vivo with CalEx flox Mice. J Neurosci 2021; 41:4556-4574. [PMID: 33903221 PMCID: PMC8260243 DOI: 10.1523/jneurosci.0085-21.2021] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/21/2021] [Accepted: 03/30/2021] [Indexed: 01/12/2023] Open
Abstract
Astrocytes exist throughout the CNS and affect neural circuits and behavior through intracellular Ca2+ signaling. Studying the function(s) of astrocyte Ca2+ signaling has proven difficult because of the paucity of tools to achieve selective attenuation. Based on recent studies, we generated and used male and female knock-in mice for Cre-dependent expression of mCherry-tagged hPMCA2w/b to attenuate astrocyte Ca2+ signaling in genetically defined cells in vivo (CalExflox mice for Calcium Extrusion). We characterized CalExflox mice following local AAV-Cre microinjections into the striatum and found reduced astrocyte Ca2+ signaling (∼90%) accompanied with repetitive self-grooming behavior. We also crossed CalExflox mice to astrocyte-specific Aldh1l1-Cre/ERT2 mice to achieve inducible global CNS-wide Ca2+ signaling attenuation. Within 6 d of induction in the bigenic mice, we observed significantly altered ambulation in the open field, disrupted motor coordination and gait, and premature lethality. Furthermore, with histologic, imaging, and transcriptomic analyses, we identified cellular and molecular alterations in the cerebellum following mCherry-tagged hPMCA2w/b expression. Our data show that expression of mCherry-tagged hPMCA2w/b with CalExflox mice throughout the CNS resulted in substantial attenuation of astrocyte Ca2+ signaling and significant behavioral alterations in adult mice. We interpreted these findings candidly in relation to the ability of CalEx to attenuate astrocyte Ca2+ signaling, with regards to additional mechanistic interpretations of the data, and their relation to past studies that reduced astrocyte Ca2+ signaling throughout the CNS. The data and resources provide complementary ways to interrogate the function(s) of astrocytes in multiple experimental scenarios.SIGNIFICANCE STATEMENT Astrocytes represent a significant fraction of all brain cells and tile the entire central nervous system. Unlike neurons, astrocytes lack propagated electrical signals. Instead, astrocytes are proposed to use diverse and dynamic intracellular Ca2+ signals to communicate with other cells. An open question concerns if and how astrocyte Ca2+ signaling regulates behavior in adult mice. We approached this problem by generating a new transgenic mouse line to achieve inducible astrocyte Ca2+ signaling attenuation in vivo We report our data with this mouse line and we interpret the findings candidly in relation to past studies and within the framework of different mechanistic interpretations.
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Affiliation(s)
- Xinzhu Yu
- Department of Physiology
- Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3704
| | | | - Baljit S Khakh
- Department of Physiology
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095-1751
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43
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Birolini G, Verlengia G, Talpo F, Maniezzi C, Zentilin L, Giacca M, Conforti P, Cordiglieri C, Caccia C, Leoni V, Taroni F, Biella G, Simonato M, Cattaneo E, Valenza M. SREBP2 gene therapy targeting striatal astrocytes ameliorates Huntington's disease phenotypes. Brain 2021; 144:3175-3190. [PMID: 33974044 DOI: 10.1093/brain/awab186] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 03/18/2021] [Accepted: 04/23/2021] [Indexed: 11/14/2022] Open
Abstract
Brain cholesterol is produced mainly by astrocytes and is important for neuronal function. Its biosynthesis is severely reduced in mouse models of Huntington's disease. One possible mechanism is a diminished nuclear translocation of the transcription factor sterol regulatory element binding protein 2 (SREBP2) and, consequently, reduced activation of SREBP-controlled genes in the cholesterol biosynthesis pathway. Here we evaluated the efficacy of a gene therapy based on the unilateral intra-striatal injection of a recombinant adeno-associated virus 2/5 (AAV2/5) targeting astrocytes specifically and carrying the transcriptionally active N-terminal fragment of human SREBP2. Robust hSREBP2 expression in striatal glial cells in R6/2 Huntington's disease mice activated the transcription of cholesterol biosynthesis pathway genes, restored synaptic transmission, reversed Drd2 transcript levels decline, cleared mutant Huntingtin aggregates and attenuated behavioral deficits. We conclude that glial SREBP2 participates in Huntington's disease brain pathogenesis in vivo and that AAV-based delivery of SREBP2 to astrocytes counteracts key features of the disease.
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Affiliation(s)
- Giulia Birolini
- Department of Biosciences, University of Milan, 20133, Milan, Italy.,Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi″, 20122, Milan, Italy
| | - Gianluca Verlengia
- Division of Neuroscience, IRCCS San Raffaele Hospital, 20132, Milan, Italy.,Department of BioMedical Sciences, Section of Pharmacology, University of Ferrara, 44121, Ferrara, Italy
| | - Francesca Talpo
- Department of Biology and Biotechnologies, University of Pavia, 27100, Pavia, Italy
| | - Claudia Maniezzi
- Department of Biology and Biotechnologies, University of Pavia, 27100, Pavia, Italy
| | - Lorena Zentilin
- International Centre for Genetic Engineering and Biotechnology, ICGEB, 34149, Trieste, Italy
| | - Mauro Giacca
- International Centre for Genetic Engineering and Biotechnology, ICGEB, 34149, Trieste, Italy.,School of Cardiovascular Medicine and Sciences, King's College London, SE5 9NU, UK
| | - Paola Conforti
- Department of Biosciences, University of Milan, 20133, Milan, Italy.,Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi″, 20122, Milan, Italy
| | - Chiara Cordiglieri
- Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi″, 20122, Milan, Italy
| | - Claudio Caccia
- Unit of Medical Genetics and Neurogenetics. Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, 20131 Milan, Italy
| | - Valerio Leoni
- School of Medicine and Surgery, University of Milano-Bicocca, 20900, Monza, Italy.,Laboratory of Clinical Pathology, Hospital of Desio, ASST Monza, 20900, Monza, Italy
| | - Franco Taroni
- Unit of Medical Genetics and Neurogenetics. Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, 20131 Milan, Italy
| | - Gerardo Biella
- Department of Biology and Biotechnologies, University of Pavia, 27100, Pavia, Italy
| | - Michele Simonato
- Division of Neuroscience, IRCCS San Raffaele Hospital, 20132, Milan, Italy.,Department of BioMedical Sciences, Section of Pharmacology, University of Ferrara, 44121, Ferrara, Italy
| | - Elena Cattaneo
- Department of Biosciences, University of Milan, 20133, Milan, Italy.,Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi″, 20122, Milan, Italy
| | - Marta Valenza
- Department of Biosciences, University of Milan, 20133, Milan, Italy.,Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi″, 20122, Milan, Italy
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44
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Herde MK, Bohmbach K, Domingos C, Vana N, Komorowska-Müller JA, Passlick S, Schwarz I, Jackson CJ, Dietrich D, Schwarz MK, Henneberger C. Local Efficacy of Glutamate Uptake Decreases with Synapse Size. Cell Rep 2021; 32:108182. [PMID: 32966786 DOI: 10.1016/j.celrep.2020.108182] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/12/2020] [Accepted: 09/01/2020] [Indexed: 01/16/2023] Open
Abstract
Synaptically released glutamate is largely cleared by glutamate transporters localized on perisynaptic astrocyte processes. Therefore, the substantial variability of astrocyte coverage of individual hippocampal synapses implies that the efficacy of local glutamate uptake and thus the spatial fidelity of synaptic transmission is synapse dependent. By visualization of sub-diffraction-limit perisynaptic astrocytic processes and adjacent postsynaptic spines, we show that, relative to their size, small spines display a stronger coverage by astroglial transporters than bigger neighboring spines. Similarly, glutamate transients evoked by synaptic stimulation are more sensitive to pharmacological inhibition of glutamate uptake at smaller spines, whose high-affinity N-methyl-D-aspartate receptors (NMDARs) are better shielded from remotely released glutamate. At small spines, glutamate-induced and NMDAR-dependent Ca2+ entry is also more strongly increased by uptake inhibition. These findings indicate that spine size inversely correlates with the efficacy of local glutamate uptake and thereby likely determines the probability of synaptic crosstalk.
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Affiliation(s)
- Michel K Herde
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Kirsten Bohmbach
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Cátia Domingos
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Natascha Vana
- Department for Neurosurgery, University Hospital Bonn, Bonn, Germany
| | | | - Stefan Passlick
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Inna Schwarz
- Institute of Epileptology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Colin J Jackson
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Dirk Dietrich
- Department for Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Martin K Schwarz
- Institute of Epileptology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany; Institute of Neurology, University College London, London, UK; German Centre for Neurodegenerative Diseases (DZNE), Bonn, Germany.
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45
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Mancini A, Ghiglieri V, Parnetti L, Calabresi P, Di Filippo M. Neuro-Immune Cross-Talk in the Striatum: From Basal Ganglia Physiology to Circuit Dysfunction. Front Immunol 2021; 12:644294. [PMID: 33953715 PMCID: PMC8091963 DOI: 10.3389/fimmu.2021.644294] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 03/16/2021] [Indexed: 01/02/2023] Open
Abstract
The basal ganglia network is represented by an interconnected group of subcortical nuclei traditionally thought to play a crucial role in motor learning and movement execution. During the last decades, knowledge about basal ganglia physiology significantly evolved and this network is now considered as a key regulator of important cognitive and emotional processes. Accordingly, the disruption of basal ganglia network dynamics represents a crucial pathogenic factor in many neurological and psychiatric disorders. The striatum is the input station of the circuit. Thanks to the synaptic properties of striatal medium spiny neurons (MSNs) and their ability to express synaptic plasticity, the striatum exerts a fundamental integrative and filtering role in the basal ganglia network, influencing the functional output of the whole circuit. Although it is currently established that the immune system is able to regulate neuronal transmission and plasticity in specific cortical areas, the role played by immune molecules and immune/glial cells in the modulation of intra-striatal connections and basal ganglia activity still needs to be clarified. In this manuscript, we review the available evidence of immune-based regulation of synaptic activity in the striatum, also discussing how an abnormal immune activation in this region could be involved in the pathogenesis of inflammatory and degenerative central nervous system (CNS) diseases.
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Affiliation(s)
- Andrea Mancini
- Section of Neurology, Department of Medicine and Surgery, Università degli Studi di Perugia, Perugia, Italy
| | | | - Lucilla Parnetti
- Section of Neurology, Department of Medicine and Surgery, Università degli Studi di Perugia, Perugia, Italy
| | - Paolo Calabresi
- Section of Neurology, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy.,Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Massimiliano Di Filippo
- Section of Neurology, Department of Medicine and Surgery, Università degli Studi di Perugia, Perugia, Italy
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46
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Onur TS, Laitman A, Zhao H, Keyho R, Kim H, Wang J, Mair M, Wang H, Li L, Perez A, de Haro M, Wan YW, Allen G, Lu B, Al-Ramahi I, Liu Z, Botas J. Downregulation of glial genes involved in synaptic function mitigates Huntington's disease pathogenesis. eLife 2021; 10:64564. [PMID: 33871358 PMCID: PMC8149125 DOI: 10.7554/elife.64564] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 04/19/2021] [Indexed: 01/01/2023] Open
Abstract
Most research on neurodegenerative diseases has focused on neurons, yet glia help form and maintain the synapses whose loss is so prominent in these conditions. To investigate the contributions of glia to Huntington's disease (HD), we profiled the gene expression alterations of Drosophila expressing human mutant Huntingtin (mHTT) in either glia or neurons and compared these changes to what is observed in HD human and HD mice striata. A large portion of conserved genes are concordantly dysregulated across the three species; we tested these genes in a high-throughput behavioral assay and found that downregulation of genes involved in synapse assembly mitigated pathogenesis and behavioral deficits. To our surprise, reducing dNRXN3 function in glia was sufficient to improve the phenotype of flies expressing mHTT in neurons, suggesting that mHTT's toxic effects in glia ramify throughout the brain. This supports a model in which dampening synaptic function is protective because it attenuates the excitotoxicity that characterizes HD. When a neuron dies, through injury or disease, the body loses all communication that passes through it. The brain compensates by rerouting the flow of information through other neurons in the network. Eventually, if the loss of neurons becomes too great, compensation becomes impossible. This process happens in Alzheimer's, Parkinson's, and Huntington's disease. In the case of Huntington's disease, the cause is mutation to a single gene known as huntingtin. The mutation is present in every cell in the body but causes particular damage to parts of the brain involved in mood, thinking and movement. Neurons and other cells respond to mutations in the huntingtin gene by turning the activities of other genes up or down, but it is not clear whether all of these changes contribute to the damage seen in Huntington's disease. In fact, it is possible that some of the changes are a result of the brain trying to protect itself. So far, most research on this subject has focused on neurons because the huntingtin gene plays a role in maintaining healthy neuronal connections. But, given that all cells carry the mutated gene, it is likely that other cells are also involved. The glia are a diverse group of cells that support the brain, providing care and sustenance to neurons. These cells have a known role in maintaining the connections between neurons and may also have play a role in either causing or correcting the damage seen in Huntington's disease. The aim of Onur et al. was to find out which genes are affected by having a mutant huntingtin gene in neurons or glia, and whether severity of Huntington’s disease improved or worsened when the activity of these genes changed. First, Onur et al. identified genes affected by mutant huntingtin by comparing healthy human brains to the brains of people with Huntington's disease. Repeating the same comparison in mice and fruit flies identified genes affected in the same way across all three species, revealing that, in Huntington's disease, the brain dials down glial cell genes involved in maintaining neuronal connections. To find out how these changes in gene activity affect disease severity and progression, Onur et al. manipulated the activity of each of the genes they had identified in fruit flies that carried mutant versions of huntingtin either in neurons, in glial cells or in both cell types. They then filmed the flies to see the effects of the manipulation on movement behaviors, which are affected by Huntington’s disease. This revealed that purposely lowering the activity of the glial genes involved in maintaining connections between neurons improved the symptoms of the disease, but only in flies who had mutant huntingtin in their glial cells. This indicates that the drop in activity of these genes observed in Huntington’s disease is the brain trying to protect itself. This work suggests that it is important to include glial cells in studies of neurological disorders. It also highlights the fact that changes in gene expression as a result of a disease are not always bad. Many alterations are compensatory, and try to either make up for or protect cells affected by the disease. Therefore, it may be important to consider whether drugs designed to treat a condition by changing levels of gene activity might undo some of the body's natural protection. Working out which changes drive disease and which changes are protective will be essential for designing effective treatments.
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Affiliation(s)
- Tarik Seref Onur
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Genetics & Genomics Graduate Program, Baylor College of Medicine, Houston, United States
| | - Andrew Laitman
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Quantitative & Computational Biosciences, Baylor College of Medicine, Houston, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, United States
| | - He Zhao
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Ryan Keyho
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Hyemin Kim
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Jennifer Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Megan Mair
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Genetics & Genomics Graduate Program, Baylor College of Medicine, Houston, United States
| | - Huilan Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Lifang Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Alma Perez
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Maria de Haro
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Ying-Wooi Wan
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Genevera Allen
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Departments of Electrical & Computer Engineering, Statistics and Computer Science, Rice University, Houston, United States
| | - Boxun Lu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Ismael Al-Ramahi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Quantitative & Computational Biosciences, Baylor College of Medicine, Houston, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, United States
| | - Juan Botas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Genetics & Genomics Graduate Program, Baylor College of Medicine, Houston, United States.,Quantitative & Computational Biosciences, Baylor College of Medicine, Houston, United States
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47
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Rajbhandari AK, Octeau CJ, Gonzalez S, Pennington ZT, Mohamed F, Trott J, Chavez J, Ngyuen E, Keces N, Hong WZ, Neve RL, Waschek J, Khakh BS, Fanselow MS. A Basomedial Amygdala to Intercalated Cells Microcircuit Expressing PACAP and Its Receptor PAC1 Regulates Contextual Fear. J Neurosci 2021; 41:3446-3461. [PMID: 33637560 PMCID: PMC8051692 DOI: 10.1523/jneurosci.2564-20.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 02/12/2021] [Accepted: 02/17/2021] [Indexed: 11/21/2022] Open
Abstract
Trauma can cause dysfunctional fear regulation leading some people to develop disorders, such as post-traumatic stress disorder (PTSD). The amygdala regulates fear, whereas PACAP (pituitary adenylate activating peptide) and PAC1 receptors are linked to PTSD symptom severity at genetic/epigenetic levels, with a strong link in females with PTSD. We discovered a PACAPergic projection from the basomedial amygdala (BMA) to the medial intercalated cells (mICCs) in adult mice. In vivo optogenetic stimulation of this pathway increased CFOS expression in mICCs, decreased fear recall, and increased fear extinction. Selective deletion of PAC1 receptors from the mICCs in females reduced fear acquisition, but enhanced fear generalization and reduced fear extinction in males. Optogenetic stimulation of the BMA-mICC PACAPergic pathway produced EPSCs in mICC neurons, which were enhanced by the PAC1 receptor antagonist, PACAP 6-38. Our findings show that mICCs modulate contextual fear in a dynamic and sex-dependent manner via a microcircuit containing the BMA and mICCs, and in a manner that was dependent on behavioral state.SIGNIFICANCE STATEMENT Traumatic stress can affect different aspects of fear behaviors, including fear learning, generalization of learned fear to novel contexts, how the fear of the original context is recalled, and how fear is reduced over time. While the amygdala has been studied for its role in regulation of different aspects of fear, the molecular circuitry of this structure is quite complex. In addition, aspects of fear can be modulated differently in males and females. Our findings show that a specific circuitry containing the neuropeptide PACAP and its receptor, PAC1, regulates various aspects of fear, including acquisition, generalization, recall, and extinction in a sexually dimorphic manner, characterizing a novel pathway that modulates traumatic fear.
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Affiliation(s)
- Abha K Rajbhandari
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Christopher J Octeau
- Department of Physiology, University of California, Los Angeles, California 90095
| | - Sarah Gonzalez
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Zachary T Pennington
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Farzanna Mohamed
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Jeremy Trott
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Jasmine Chavez
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Erin Ngyuen
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Natasha Keces
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Weizhe Z Hong
- Department of Neurobiology, University of California, Los Angeles, California 90095
| | - Rachael L Neve
- Gene Delivery Technology Core, Massachusetts General Hospital, Boston, Massachusetts, California 02114
| | - James Waschek
- Department of Psychiatry, University of California, Los Angeles, California 90095
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, California 90095
- Department of Neurobiology, University of California, Los Angeles, California 90095
| | - Michael S Fanselow
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
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48
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Sokolova D, Childs T, Hong S. Insight into the role of phosphatidylserine in complement-mediated synapse loss in Alzheimer's disease. Fac Rev 2021; 10:19. [PMID: 33718936 PMCID: PMC7946395 DOI: 10.12703/r/10-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The innate immune system plays an integral role in the brain. Synaptic pruning, a fundamental process in developmental circuit refinement, is partially mediated by neuroimmune signalling at the synapse. In particular, microglia, the major tissue-resident macrophages of the brain, and the classical complement cascade, an innate immune pathway that aids in the clearance of unwanted material, have been implicated in mediating synapse elimination. Emerging data suggest that improper signalling of the innate immune pathway at the synapse leads to pathological synapse loss in age-related neurodegenerative diseases, including Alzheimer's disease. Now the key questions are whether synapses are targeted by complement and, if so, which synapses are vulnerable to elimination. Here, we review recent work implicating C1q, the initiator of the classical complement cascade, and surrounding glia as mediators of synapse loss. We examine how synapses could undergo apoptosis-like pathways in the Alzheimer brain, which may lead to the externalisation of phosphatidylserine on synapses. Finally, we discuss potential roles for microglia and astrocytes in this 'synaptic apoptosis'. Critical insight into neuroimmune regulatory pathways on synapses will be key to developing effective targets against pathological synapse loss in dementia.
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Affiliation(s)
- Dimitra Sokolova
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
| | - Thomas Childs
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
| | - Soyon Hong
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
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49
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Brymer KJ, Barnes JR, Parsons MP. Entering a new era of quantifying glutamate clearance in health and disease. J Neurosci Res 2021; 99:1598-1617. [PMID: 33618436 DOI: 10.1002/jnr.24810] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/22/2021] [Accepted: 02/01/2021] [Indexed: 12/21/2022]
Abstract
Glutamate transporter proteins, expressed on both neurons and glia, serve as the main gatekeepers that dictate the spatial and temporal actions of extracellular glutamate. Glutamate is essential to the function of the healthy brain yet paradoxically contributes to the toxicity associated with many neurodegenerative diseases. Rapid transporter-mediated glutamate uptake, primarily occurring at astrocytic processes, tightens the efficiency of excitatory network activity and prevents toxic glutamate build-up in the extracellular space. Glutamate transporter dysfunction is thought to underlie myriad central nervous system (CNS) diseases including Alzheimer and Huntington disease. Over the past few decades, techniques such as biochemical uptake assays and electrophysiological recordings of transporter currents from individual astrocytes have revealed the remarkable ability of the CNS to efficiently clear extracellular glutamate. In more recent years, the rapidly evolving glutamate-sensing "sniffers" now allow researchers to visualize real-time glutamate transients on a millisecond time scale with single synapse spatial resolution in defined cell populations. As we transition to an increased reliance on optical-based methods of glutamate visualization and quantification, it is of utmost importance to understand not only the advantages that glutamate biosensors bring to the table but also the associated caveats and their implications for data interpretation. In this review, we summarize the strengths and limitations of the commonly used methods to quantify glutamate uptake. We then discuss what these techniques, when viewed as a complementary whole, have told us about the brain's ability to regulate glutamate levels, in both health and in the context of neurodegenerative disease.
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Affiliation(s)
- Kyle J Brymer
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Jocelyn R Barnes
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Matthew P Parsons
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
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Nagai J, Yu X, Papouin T, Cheong E, Freeman MR, Monk KR, Hastings MH, Haydon PG, Rowitch D, Shaham S, Khakh BS. Behaviorally consequential astrocytic regulation of neural circuits. Neuron 2020; 109:576-596. [PMID: 33385325 DOI: 10.1016/j.neuron.2020.12.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Astrocytes are a large and diverse population of morphologically complex cells that exist throughout nervous systems of multiple species. Progress over the last two decades has shown that astrocytes mediate developmental, physiological, and pathological processes. However, a long-standing open question is how astrocytes regulate neural circuits in ways that are behaviorally consequential. In this regard, we summarize recent studies using Caenorhabditis elegans, Drosophila melanogaster, Danio rerio, and Mus musculus. The data reveal diverse astrocyte mechanisms operating in seconds or much longer timescales within neural circuits and shaping multiple behavioral outputs. We also refer to human diseases that have a known primary astrocytic basis. We suggest that including astrocytes in mechanistic, theoretical, and computational studies of neural circuits provides new perspectives to understand behavior, its regulation, and its disease-related manifestations.
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Affiliation(s)
- Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; RIKEN Center for Brain Science, 2-1 Hirosawa Wako City, Saitama 351-0198, Japan
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 514 Burrill Hall, 407 S. Goodwin Ave, Urbana, IL 61801, USA
| | - Thomas Papouin
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, Campus Box 8108, 660 South Euclid Ave., St. Louis, MO 63110, USA
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Marc R Freeman
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Kelly R Monk
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Michael H Hastings
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - David Rowitch
- Department of Paediatrics, Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK; Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
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